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Ambulatory blood pressure biosituational feedback and systolic blood pressure estimation

University of Florida Institutional Repository

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AMBULATORY B LOOD PRESSURE BI OSITUATI ONAL FEEDB ACK AND SYSTOLI C BLOOD PRESSURE ESTI MATION By SANDRA WOLFE CI TTY A DISSERTATI ON PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVE RSITY OF FL ORIDA I N PARTIAL FULFI LL MENT OF THE REQUIREMEN TS FOR THE DEGREE OF DOCTOR OF PHIL OSOPHY UNIVERSI TY OF FLORI DA 2003

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This dissertation is dedicated to my husband and c hildren, Jef f, Me g ha n, a nd Ma tth e w; in l ov ing me mor y of Er ic A. Wolf e ; and to my three wonder ful families, the McGr og ans, the Wolfes, and the Citt y s. Thank y ou to J eff for be ing a wonder ful frie nd, husband, and f ather Thank y ou to Meg han and Ma tthew for be ing the best littl e re sear cher s, data c ollectors, and c hildren in the world. Thank y ou to my mom, L iz, for helping w ith baby sitti ng and g randma things. Thank y ou to my sister, Susan, for he r support throug h this process. I love y ou all very much! Thank y ou, God!

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iii ACKNOWLEDGMENTS I gr at ef ul ly a ck no wl ed ge th e a ss is ta nc e o f m y di ss er ta ti on ch ai rp er so n, Ca ro lyn Yucha, PhD, for her mentoring, g uidance, humor, encourage ment, patience, and wisdom throughout the course of my 4 years a t the University of F lorida. I grate fully acknowledg e the support of the University of Florida College of Nursing, UF College of Nursing Office for Research Support, N. F lorida/S. Georgia VA Health System, and Sigma T heta Tau Alpha Theta Chapter I nternational Nursing Honor Society for partial funding of th is project. I am extremely grateful to Maude Rittman, PhD for her g uidance and mentoring during m y Pr edoctor al Nurse Fellows hip at the Gainesv ille VAMC. I g ratefu lly acknowledge Ms. Susan Nadeau and the staff at the Brain Rehabilitation Research Cente r and Rehabilitation Outcomes Research Center for their a ssistance with acquiring research office space and subject recr uitment. I also would like to extend my deepest appreciation to my dissertation committee members—Ma ude Rittman, PhD, Joyce Stechmiller, PhD, and Keith Berg, PhD—for their contr ibutions and support of this project.

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iv TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................................ iii ABSTRACT ........................................................... vi CHAPTER 1 INTRODUCTI ON .................................................... 1 Definition and Scope of the Problem ...................................... 1 Problem Statement .................................................... 7 Purposes of the Study .................................................. 8 Hypotheses .......................................................... 9 Definitio ns of Ter ms .................................................. 9 Assumptions ........................................................ 11 Limitations ......................................................... 11 Significance of the Study .............................................. 11 2 REVI EW OF L ITER ATURE .......................................... 13 Theories of Hy pertension Development .................................. 13 Systolic Hy pertension ................................................ 25 Issues Surrounding the Tre atment of Hy pertension .......................... 26 Biosituat ional Factors Associated with High BP ............................ 31 BP Awareness and Estimation .......................................... 38 Educational Level and He alth Disparities ................................. 49 Ambulatory BP Monitoring ............................................ 50 Summary .......................................................... 52 3 PROCEDURES AND METHODS ...................................... 53 Resea rch Des ign ..................................................... 53 Population and Sample ............................................... 53 Inc lusion and Exclusion Cr iteria ........................................ 55 Setting ............................................................ 56 Researc h Variab les and I nstrumen ts ..................................... 56 Study Protocol and Procedures ......................................... 63 Methods of Statistical Analyses ......................................... 68

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v 4 RESULTS ......................................................... 71 Descrip tive Resul ts .................................................. 71 Analytic Results for Hy potheses ........................................ 75 Hypotheses ......................................................... 78 5 DISCUSSION AN D RECOMMENDATIONS ............................. 93 Discussio n of Result s ................................................. 93 Conclusions ....................................................... 105 Implications for Clinical Practice ...................................... 106 Recommendat ions for Fut ure Research .................................. 108 AP PE NDIX A PRE-/POSTTR AIN ING SBP ESTI MATI ON FORM ....................... 110 B SBP ESTI MATI ON STUDY TRAI NIN G FORM ......................... 111 C SBP ESTI MATI ON STUDY TRAI NIN G FORM ......................... 113 D HEAL TH HI STORY FOR M .......................................... 115 REFERENCES ....................................................... 117 BIO GRAPHI CAL SK ETCH ............................................. 126

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vi Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy AMBULATORY BLOOD PRESSURE BIOSITUATIONAL FEEDBACK AND SYSTOLIC BLOOD PRESSURE ESTIMATION By Sandra Wolfe Citty May 2003 Chair: Carolyn Yucha Major Department: Nursing to be a devastating threat throughout the United States and worldwide. From 1987 to 1997, the death rate from high blood pressure increased by 13.1%. Difficulties indetection and treatment exist because hypertension is a relatively silent disease, for whichpatients are often asymptomatic and are feeling well. Because of the lack of observablesymptoms associated with high blood pressure, patients with hypertension often havedifficulty prescribing meaning to their disease threat or treatment requirements. Theprimary purpose of this research was to determine if subjects with hypertension canimprove their awareness of their systolic blood pressure after participating in theambulatory blood pressure and biosituational self-awareness training intervention. Arepeated measure, pretest/posttest design was used for this study. Thirty-nine adulthypertensive subjects participated in the study. There were no significant differencesamong the group of hypertensives after training compared to before training, using a In an age of technological advances and medical breakthroughs, hypertension continues

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vii paired samples t-test. There were, howe ver significant differenc es in improvement of estimating SBP among the subgroup of co llege-educated hy pertensives (p = 0.04) and between the groups who used and did not use a ntihypertensive medica tions (p = 0.05). Hypertensive s who did not take medications showed significant improvement compare d to antihypertensive medic ation users. This study provides support f or using feedback metho ds to impro ve the abili ty to est imat e BP in c ertai n popu lati ons, s pecifi cally col lege educated hy pertensives and hy pertensives who are not taking antihy pertension medications, and suggests that BP awar eness may be improved in selected people using feedback methods.

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1 CHAPTER 1 INTRODUCTI ON This chapter introduces concepts that are under investigation including the significance of hy pertension, problems with detection and treatment of high blood pressure (BP), factors associate d with dismal treatment rates, potential manifestations or factors associated with high BP levels, an d estimation of BP. This chapter will describe the definition and scope of the problem, the main resear ch problem to be investigated, and the significance of the study The definition of major terms, assumptions, and limitations will also be described. Definition and Scope of the Problem Hy pertens ion is def ined as sy stolic B P (SBP) of 140 mmHg or gre ater, di astolic BP (DBP) of 90 mmHg or gre ater, or taking antihy pertensive medication. In the United States, people with hyperte nsion comprise a rapidly growing subset of the population. Approximately 50 million Americans have hig h BP. High BP was the primary cause of death for 44,435 Americans in 1998 and contributed to about 210,000 dea ths (American Heart Association [AHA], 2003b). Approximately 95% of people with hyperte nsion have essential (or primary ) hyperte nsion, for which no clear cause ca n be identified. From 1987 to 1997, the death rate from high B P increased by 13.1% (AHA, 2000). Treatment of hy pertension continues to be plagued by dismal statistics in that only 27.4% of Americans with high BP are ade quately c ontrolled on medication (AHA, 2003a).

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2 Elevated systolic B P (SBP) specifically ha s been associated with increased morbidity and mortality especially in the older population. Prospective studies have shown that there is a st rong, contin uous, graded, i ndependent as sociation between SBP and the risk of coronary heart disease, stroke, and end-stag e renal disease (He & Whelton, 1999). Additionally, data from the National He alth and Nutrition Examination Survey (NHA NES) II I found that isolated sy stolic hypertension was the most fre quent subt ype of unco ntrol led hypert ensio n, esp ecial ly in sub jects over 5 0 years of a ge (Franklin, Jacobs, Wong, L’I talien, & LaPuerta, 2001) The incidence and severity of complications increase with the duration and severity of hyperte nsion (Kaplan, 1998; Lackland, 2000). Be cause of this, it is crucial to identify and treat high BP, and specifically hig h SBP, in order to reduce the risk of advanced c ardiovascular disease and its associated morbidity and mortality Inadequate adhe rence to antihy pertensive therapy is a major challenge and con tri but es t o el eva ted BP l eve ls in two -th ird s of all pat ien ts wit h hyp ert ens io n (J NC V I, 1997). One of the major obstacles in the diagnosis and trea tment of hypertension is that it has a ver y i nsidi ous c ours e, wh ich th e pat ient o ften fail s or r efus es to r ecog nize because he or she may continue to “feel good.” Noncompliance w ith antihypertensive therapy ha s been cited as the major cause of trea tment failure (AHA, 2003c). Noncompl iance is a multi-f aceted issue tha t results f rom vary ing beh avioral social, logistical, economic, and practical fa ctors (Miller, Hill, Kottke, & Ockene, 1997). Failure to comply w ith prescribed medication regimens or other ther apies can affect patients’ health adversely as patients may fa il to improve, worsen, or relapse. Complianc e not only affec ts the imme diate pa tient but th e entire United Sta tes heal th care sy stem and economy. Nonc ompliance accounts for 100 billion dollars in health care

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3 and productivity costs in the United States. The c osts of hospitalizations and practitioner visits caused by noncompliance account for 8.5 billion dollars annually (Task Force for Compliance, 1994). Several factors have been assoc iated with antihypertensive adherence patterns including whether or not sy mptoms affect daily life or work, family history of hypertension, household composition, perc eived threat of complications, and perceived need and perceived effe ctiveness of medications (McLa ne, Zy zanski, & Flocke, 1995; Meyer, L eventhal, & Gutmann, 1985). Because hypertension is g enerally thoug ht of as an asympt omati c dise ase and due to the la ck of d efini tive s ymptoms assoc iated with high BP, it ca n be diff icult for patients t o adequa tely prescr ibe mean ing and importanc e to their disease process and treatment options (McL ane et al., 1995). If hig h BP were associated with observable sy mptoms, it may be possible to improve early recognition of the disease, improve its treatment compliance and improve outcomes. Over the past seve ral y ears, mo re atten tion has be en paid to prevent ive heal th care a nd patien ts have be en viewe d more in te rms of be ing hea lthcare consumer s and less as being passive participants of the healthca re process. Noncompliance in the patient with hy pertens ion comes in the fa ce of g rowing consumer empower ment amon g patie nts (Skelton, 1997). More than ever, people are try ing to improve their health by particip ating in their ca re (Rote r, Stashe fsky -Marg elit, & Ru dd, 2001) In a ddition to pharmac ologic t herapy biofee dback the rapy has been used succ essfully to assist pe ople in treating and preventing major hea lth problems, such as hyperte nsion, chronic pain, and anxiety (Ferna ndez & Beck, 2001; Knost, Flor, Birbaumer & Schugens, 1999; La l et al., 1998). Biofeedback therapy has been used successfully in both research and clinical setting s to lower BP in hy pertens ive patie nts (L al et al., 1998; Yuc ha et al. 2001). T hese

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4 therapies would be strengthened if patients we re more aware of their hig h BP or if they had symptoms associated with hig h BP that could be coupled with therapy Healthy People 2010 identified goals to advance the preve ntion, detection, and treatment of hypertension, stroke, a nd heart disease. To increase public attention, awa reness, and treatment, goal number 12-12 states that there “ should be an increase in the proportion of adults who have ha d their B P measure d within the preced ing 2 y ears an d can sta te whether their BP was normal or high” ( Healthy People 2010, 2003). As patients with hypertension strive to bec ome more involved in their healthcare decisions, treatments need to be found that focus on the patient as the mana ger of his/her own heal th. High BP is a phe nomenon th at gene rally is not asso ciated w ith specif ic symptoms or signs (AHA, 2003c ). Because of this, patients with hy pertension often have difficulty understanding the threat of the disease or the treatments require d to manage the disease. In disorders with observa ble symptoms, such as diabetes mellitus, cong estive heart failure or seizures, patients may be more motivated to seek and continue treatment. Little is known a bout the e xtent to whic h hy pertens ive patie nts are a ware of their high BP; however, several rese arch studies and clinical experiences have shown that peo pl e ca n be mo re a war e of th eir BP l eve ls aft er d iff ere nt type s of fee dba ck t rai ni ng. If patients were aware of their hig h BP episodes, better-tailored treatment modalities may be developed and adherence to ther apeutic treatment may be improved resulting in better patient o utcomes. For examp le, biofe edback or rela xation ther apies co uld be use d to assist patients in lowering their BP during episodes of hig h BP. While ther e is contin ued contr oversy over whe ther the re are definitiv e sy mptoms associated with BP, it is generally believed that most patients with hypertension c annot accurately tell if their BP is elevated (Fahrenberg Franck, Baas, & Jost, 1995).

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5 However, some clinicians and researc hers report that certain patients are able to detect when their BP is elevated (Barr, Penne baker, Watson, 1988). These patients often report vague sy mptoms that are associated with their high BP. Sy mptoms such as headache, racing heart, s weaty hands, c old/warm hands, tig ht stomach muscula r tension dizziness, blurred vision, lig htheade dness, te nsion, pal pitations, flushed f ace, an d warm/c old extremities have been correlated with variations in BP (Bulpitt, Dollerly & Carne, 1976; Pennebaker, Gonder-Frede rick, Stewart, Elfman, & Skelton, 1982). There are many hypotheses behind the de velopment and maintenance of hyp ertensio n. These theorie s provide a frame work for understa nding ho w patient s with high BP can be helped to recog nize the subtle signs and symptoms. One hy pothesis of hypertension deve lopment is the sympathetic nervous sy stem theory of hy pertension development. This hypothesis descr ibes hypertension as a result of over-stimulation of the SNS. To substantiate SNS overactivation, several studies of patients with essential hypertension demonstra te increased levels of plasma norepinephrine a nd elevated norepinephrine spillover. Patients with borderline and essential hy pertension have an increased sy mpathetic and a decreased para sympathetic drive (Ra hn, Barenbrock, & Hausberg, 1999). I t is hypothesized, and highly debated, whether sy mpathetic nervous sys tem (SNS) a ctivation is a trig ger fo r high B P (defen se reac tion) or if SNS activa tion is due to a secondary phenomenon (e.g., endothelial or barore ceptor dysfunc tion). Alterat ions and/o r uncompe nsated in crease s in SNS act ivity in hy pertens ives may cause subtle physical signs a nd symptoms. I ncreased SNS activity and early hypertension ar e often characterized by an increased heart rate, c ardiac output, and renal vascular resistance. The sy mpathetic nervous system e licits a “fight or flight” response when confronted with a stimulus, such as when the person is in an emerg ency or stre ssful

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6 situation. Additionally, sy mptoms that are related to increased SNS activity have been reporte d in hy pertens ives and h ave bee n corre lated wit h high B P episodes (Carels Sherwood, & Blumenthal, 1998). Potential m anifesta tions of inc reased SNS activit y in clude inc reased heart r ate and stroke volume (cardiac output), increase d cardiac contractility and venous return, renal retention of sodium and water, increase d thirst, increased venous tone, increased angiotensin II increased peripheral resistance increased local vasoconstrictors/reg ulators (e.g., endothelin), increased blood viscosity and decreased local vasodilators/reg ulators (e.g., nitric oxide). Symptoms associate d with high BP may be related to overstimulation or oversensitivity of the SNS in hy pertensive individuals (Esler, 2000; Kaplan, 1998; Rahn, Barenbrock, & Hausbe rg, 1999). It has been repor ted that individuals, both normotensive and hyperte nsive, estimate their BP levels by using both internal sensory and external situational information (Barr et al., 1988). Estimations and beliefs about BP leve ls may or may not be accurate, but they are important because people act upon them. I n fact, Pennebaker et al. (1982 ) sugg est that va riations i n BP are correl ated to di ffere nt sy mptoms and that a person can monitor his or her BP by monitoring symptoms. I nterestingly in studies where b oth normot ensive a nd hy pertens ive peopl e were asked to e stimate th eir BP le vels, estimate d BP was s trongly associa ted with sy mptoms and moods (B aumann & Leve nthal, 1985) and with feelings of phy sical tenseness and phy sical activity (F ahrenberg et al., 1995). Several studies on whether or not people can acc urately estimate the ir BP have been performed. The findings have been fraught with much speculation and conf licting results (Barr et al., 1988; Baumann & Leventhal, 1985; Brondolo, Rosen, Kostis, &

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7 Schwartz, 1999; Cinciripini, Epstein, & Martin, 1979; Fahrenberg et al., 1995; Greenstadt, Shapiro, & Whitehead, 1986; L uborsky et al., 1976; Shapiro, Tursky & Schwartz, 1970). An important variable among these studies was the a ddition of a feedback intervention. Among the fee dback intervention-ty pe studies, all showed an improvement in BP discrimination after feedback (B arr et al., 1988; Brondolo et al., 1999; Cinciripini et al., 1979; Greenstadt et al., 1986; Luborsky et al., 1976; Shapiro et al., 1970). Differ ent ty pes of fe edback have be en used to assist subj ects in le arning to recognize sy mptoms, situations, and factors that are associated with their BP levels. Barr, Pennebaker, and Watson (1988) provide d normotensive subjects actual biositu ational fact ors (e.g., symptoms moods, s ituation s) that were rel ated to thei r SBP levels. They found tha t 71.4% of the subjects in the biosituational feedback group had significant accuracy correlations compared with 31.3% of the subjects in the control (no feedback) group. Additionally providing normotensive (Barr et al., 1988; Cinciripini et al., 1979; Greenstadt et al., 1986) and hy pertensive subjects’ (Brondolo et al., 1999 Lubor sky et al., 19 76; ) know ledge o f their a ctual BP levels ha s also bee n used to improve a ccurac y in estimatin g BP lev els. Problem Statement Becau se of the continue d preval ence an d inciden ce of hy pertens ion and its complications, there must be more research foc used on testing detection and intervention strategies, as well as improving patient compliance (AHA, 2003c; Miller, Hill, Kottke, & Ockene, 1997). The American Hea rt Association Expert Panel on Compliance (Miller et al., 1997) reported that a multilevel approach fea turing both behavioral and educational

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8 strategies was needed to assist patients and provider s in improving compliance (Miller, Hill, Kottke, & Ockene, 1997). Because the majority of BP feedback intervention-ty pe studies have been perfor med on nor motensive healthy voluntee rs, it is unk nown whe ther adu lts with hypertension ca n accurately estimate their BP or if this awareness can be improve d through BP or bios ituationa l feedba ck. Spec ifically it is unkno wn if hy pertens ive adult s can estimate their SBP more accurately after participating in ambulatory BP feedback and biosituational self awareness training. Purposes of the Study The purp oses of th e study are as f ollows: 1. To determine if there are differ ences in the mean absolute difference (AD) among adult hy pertensives after training compare d to before training. 2. To determine if there are differ ences in the mean improvement of estimating SBP among college-e ducated hype rtensives versus noncollegeeducated hy pertensives. 3. To determine if college-educa ted hypertensive s decrease their mean AD post train ing com pared t o pret raini ng. 4. To determine if there are differ ences in the mean improvement of estimatin g SBP be tween hy pertens ives whos e body mass inde x (BMI ) is $ 30 and hyperte nsives whose BMI is < 30. 5. To determine if there are differ ences in the mean improvement of estimatin g SBP be tween ma le hy pertens ives and f emale hy pertens ives. 6. To determine if there are differ ences in the mean improvement of estim ating S BP bet ween hyper tensi ves wh o are < 4 8 years of a ge compared with those who are $ 48 years of age. 7. To determine if there are differ ences in the mean improvement of estimating SBP between hy pertensives who use antihy pertensive medicati ons and tho se who do n ot use ant ihy pertens ive medic ations.

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9 Hypotheses The hypotheses investig ated are listed below: 1. Adult hypertensives diffe r significantly in their mean improvement of estimating SBP after the ambulatory BP awareness training intervention, compared with before the training interve ntion. 2. College-educated hy pertensives differ significantly from noncollegeeducate d hy pertens ives in the ir mean im proveme nt of estim ating SB P. 3. College-educated hy pertensives decrease their mean A D posttraining compa red to pretr ainin g. 4. Hypertensive s with a BMI < 30 diffe r significantly from hyperte nsives wit h a B MI $ 30 in their mean impr ovement o f estimat ing SBP. 5. Male hyper tensives differ significantly in their mean improvement of estimatin g their SBP compa red to fe male hy pertens ives. 6. Hypertensive s < 48 year s of age differ significa ntly in their improvement of estima ting SBP c ompared to hy pertens ives $ 48 years a nd older. 7. Hy pertens ives using antihy pertens ion medic ation diff er sign ificantl y in their mean improvement of estimating SBP compared with hy pertensives not taking medicati ons. Definitio ns of Ter ms The absolute difference (AD) is defined as the absolute value of the mean difference between ac tual and estimated SBP. The absolute difference wa s calculated for mean actual SBP day s 1, 2 and 3, and 4 and mean estimated SBP day s 1, 2 and 3, and 4. Actual SBP is defined as that which i s measured us ing the ambul atory BP monitor; it is viewed as a continuous variable with parameters defined as me an, standard deviation, and variance. Ambulatory BP fe edback is defined as those BP readi ngs from the am bulatory BP monitor that can be viewed by the patient on the unblinded LCD screen.

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10 Ambulatory BP monitoring is defined as an automatic, noninvasive cuffoscillimetric recorder (Model 90207, SpaceL abs, Inc., Redmond, WA) which measure s ambulato ry BP. Subjec ts wear t he ambula tory BP monitor cuff in a similar fa shion as a standar d manual s phy gmomano meter. H owever the ABP monitor is p reprog rammed v ia specialized software to automatically measure BP at preset intervals throughout the da y and nig ht. The su bject we ars the c uff aro und his/he r upper f orearm and the ma in unit is strapped around the waist via a strap or belt. ABP monitoring is a reliable and naturalistic method for obtaining BP readings while subje cts are in their normal environm ent. Biosituational feedback is define d as fee dback re lated to b iologic al, situat ional, psy cholog ical fac tors that t he subjec t has exper ienced. Biositua tional fe edback in this study is provided to the subject by providing the subject with information on their actual SBP, self-reports of their estimated SBP, and self-repor ts of their moods, symptoms, and activitie s during BP measu rement. A blinded-LCD screen is the panel on the ABP monitor that displays the time of day, but does not d isplay the physiologic dat a (i.e., the p atient canno t view the BP measurement). Estimated SBP is defined as that which is estimated by each subject; it is viewed as a continuous variable. Hypertension is defined as SBP of 140 mmHg or grea ter, diastolic BP of 90 mmHg or greater, and/or taking antihype rtensive medication. Hy pertens ive subje cts are ide ntifi ed as h ypertens ive if they have B P read ings greater than 140/90 on both of the two scree ning BP measurements or they are taking antihy pertens ive medic ations.

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11 The mean improvement is defined as the absolute value of the mean differ ence of day 1 (mea n actual SBP minus mean estimated SBP) minus the absolute value of the mean difference of day 4 (mean difference of ac tual SBP minus estimated SBP). An unblinded-LCD screen is the pan el on the A BP monitor that displa ys t he time of day and a llows the subject to view the SBP, DBP, and heart rate. Assumptions Th e f ol lo wi ng as su mp ti on s w er e m ad e i n t hi s s tu dy: 1. Pa rt ic ip an ts ha ve so me kn ow le dg e o f t he ir he al th st at us i nc lu di ng BP an d w ays to treat h igh BP. 2. Participa nts have s ome opinio ns about th eir BP pa tterns an d factor s relatin g to their hig h BP. 3. Participa nts have a ccess to various s ources o f informa tion about high BP. 4. Parti cipan ts may hav e symptom s and p atter ns th at are a ssoci ated w ith t heir h igh BP. 5. People with high BP may have alterations in autonomic nervous sy stem function ing that may predispo se them to h ave sy mptoms duri ng hig h BP episo des. 6. Symptoms, patterns, and causes of high BP vary from person to person. 7. Patients with hypertension have va riability in their SBP of at least 30-50 mmHg in a 24-hour period. Limitations The generalizability of the results of this study is limited to adult hy pertensive persons w ho live in th e North Ce ntral Fl orida ar ea. Des pite this lim ited ge ograp hic range, the population is believed to be similar to the population of hy pertensive persons in other parts of the United States. Significance of the Study Hypertension is a major cause of death in the U.S. and worldwide. Only about one quarter of adults with hy pertension are being adequate ly controlled on medications

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12 (AHA, 2003c). Because of this, there will be increased economic burden and incre ased morbidity and mortality associated with high BP. Hy pertension is difficult to treat for a variety of r easons. One issue is that hype rtension is a relatively a symptomatic disorder and patients may not eve n realize that their BP is elevated. Because there has been limited re search inquiry into hy pertens ives’ aw arenes s of their BP level s, it is ge nerally unknown whether hy pertensives can improve their ability to estimate their BP. Research has indicated that SBP is an important determinant to the risk of coronary heart disease, stroke, and end-stage renal disea se (He & Whelton, 1999). Because of the importance of SBP prediction and modification, this study examined the ability of adult hyperte nsive persons to estimate their SBP before and after a biosituational feedback training interve ntion. A be tter unde rstandin g of est imation of SBP among hyp ertensiv es will encourage resea rchers to study a nd develop new and better-tailored treatment modalities. This study also utilize d ABP monit oring a nd a self -repor t diary to assist a dults with hyp ertensio n to lear n more ab out their B P pattern s and asso ciated f actors. Finally this study examined differenc es between different groups of hypertensives. This informa tion will shed l ight on po tential su b-grou ps that may be bette r or wors e at estim ating th eir SBP and may enc ourage a more focused inquiry into SBP estimation and biosituational feedba ck train ing. Add itionally if hy pertens ives can improve th eir abili ty to estimate their SBP levels, there may be improved adherence to medications, improved hyp ertensio n therap ies, and i mproved o utcomes.

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13 CHAPTER 2 REVI EW OF L ITER ATURE This chap ter will pr esent a l iteratu re revi ew of the following areas o f resea rch: theories of hype rtension development, systolic hy pertension, role of sy mpathetic nervous system in hy pertension, issues surrounding the treatment of hy pertension, biosituational factors associated with high BP, BP estimation, and a mbulatory BP monitoring. A summary linking t hese ar eas tog ether to provide a resea rch rat ionale f or this stud y w ill conclude this chapter. Theories of Hy pertension Development There have been severa l mechanisms that have been implicated in hy pertension development. These mechanisms include impaired baror eceptor function, increased sym pathetic nervous s yst em activi ty, impaire d endothe lial func tion, and/ or struc turaladaptive changes in the vascular w alls. Impaired Bar oreceptor Function and Baro receptor Resetting The baroreceptor mechanism in the c entral nervous sy stem assists with the regulation and control of arterial pre ssure. Baroreceptors a re nerve endings that lie in the walls of large arteries and a re stimulated when stretched. This reflex is initiated by pressure-sensitive receptors, located in the walls of the large arteries of the neck and thoraci c regi ons, car otid arte ry and the a ortic a rch. The barore ceptors respond r apidly to acute drops or elevations in BP. The barore ceptor signal is transmitted, enters the medulla, and stimulates either the sympa thetic nervous sy stem (SNS) (if BP is too low)

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14 or the parasy mpathetic nervous system (P NS) (if BP is too high). Stimulation of the SNS promotes the secretion of both norepinephrine (NE) and epinephrine and causes vasoconstriction in vascular smooth muscles and blood vessels and increase d strength of heart contraction. Stimulation of the PNS would promote the secretion of acety lcholine and cause vasodilation of the veins and arterioles a nd decreased heart rate a nd strength of contrac tion. The b arorec eptor me chanism is an extre mely powerf ul and ef fective entity within th e nervous and c ardiovascul ar systems for shortterm regulati on of BP (Chapleau, Cunningham, Sullivan, Watchel, & Abboud, 1995; Harring ton, Murray, & Ford, 2000; Seeley Stephens, & Tate, 1998). One of the problems with the baroreceptor sy stem in the long-term regulation of arterial pressure is that the barorece ptors are continually “reset” after 1 to 2 day s of prolonged pres sure expos ure. Conseq uently, they are only effective if the chan ge in BP is acute or not prolonged. For example, if the pre ssure rises from the normal 100 mmHg to 170 mmHg, there would be an acute an d immediate response from the baroreceptor reflex (vasodilation). The rate of impulse firing is ra pid and extremely acute, a nd then diminishes over the course o f a few s econds The ra te of impul se firing continue s to decline over a period of 1 to 2 day s until ultimately the rate of fir ing ceases, despite the fact that the arterial pressure re mains at 170 mmHg. Thus, the baroreceptor ha s been “reset” to be accustomed to a consistently high BP level (Chapleau et al., 1995; Guy ton & Hall, 1996). It is interesting to note that studies have show n that young, mild or borde rline hyp ertensiv e patien ts have a n increa se in BP v ariabili ty a nd skelet al muscle sym pathetic nerve activity, a nd display increa sed baroreceptor activity This may be a c ompensatory finding that is associated with increased sy mpathetic nerve activity whereby the

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15 baroreceptors are attempting to a djust the BP toward more normal levels. I n established hypertension assoc iated with myocardia l hypertrophy and decreased my ocardial stretchability, barorec eptor function has been shown to decline (Chapleau e t al., 1995). The barorecepto r reflex may also not be effective in long-term regula tion of BP because of the structural and functional ch anges that are seen in the blood vessels of patients with hypertension. B ecause of the anatomical location of the ba roreceptor nerve endings, dysf unction of the vessel lumen/endothelium may decrease the barorec eptor pressure-sensor effectivene ss (Chapleau et al., 1995; Seeley et al., 1998). Another problem o f shorta nd long -term ba rorece ptor reg ulation of arteria l BP is that even under conditions of “normal” ag ing, baroreceptor function and other cardiop ulmonary neural r egulat ory functio ns have b een show n to be les s effec tive with age. I n animal st udies, the effec ts of adm inistratio n of ace tylc holine on h eart ra te (i.e., brady cardia) are more pronounce d in elderly nor motensive subjects than in young er controls The bar orecep tor contr ol of BP i n normal s ubjects is reporte d to be com parable to that of the young er controls; however, the response to the stimulus (either hig h or low BP) is sluggish and slower. Thus, barorec eptor control of BP becomes impaired with the aging process howeve r to a less er deg ree tha n heart r ate reg ulation. St udies hav e also shown that there is impairment in the cardiogenic stre tch receptors located in the cardiopulmonary region that are associated w ith aging (Chapleau et al., 1995; Fauve l et al., 2000; Giannattasio et al., 1994). Impa ired baroreceptor function and bar oreceptor resetting may lea d to uncompensated increases or decr eases in BP. It remains unc lear whether baroreceptor dy sfunction is the cause or effect of hy pertension.

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16 Sympathetic Hy peractivity The ory In the sy mpathetic hypera ctivity theory of hyperte nsion, hypertension is caused by a n abnorma lly i ncreas ed stimula tion of th e sy mpathetic nervous s yst em. I ncreas es in catecholamine stimulation effect BP by increasing heart rate stroke volume, and peripheral resistance. Factor s that may be a ssociated with increased sy mpathetic outflow and increased total peripheral vascular resistance in essential hy pertension include baroreflex re-setting; gene tic composition; stress; altered renin-angiotensin-aldosterone mechanisms; alterations in circulating hormones/substances; structura l-adaptive changes in vascular walls; endothelial dy sfunction; endothelial derived relaxing and contrac ting factor s; and memb rane an d intrac ellular m echanis ms, includ ing impa ired adr energ ic receptor numbers and ty pes. The increase in SNS activity stimulates the release of catecholamines to effect specific tar get organs including the vascular smooth muscle, blood vessels, kidneys, and hea rt. Effects of increased SNS activity include increased heart rate and stroke volume (cardia c output), increased cardiac c ontractility and venous return, renal retention of sodium and water, inc reased thirst, increased venous tone, increased angiotensin I I, increased pe ripheral resistance, increase d local vasoconstrictors/regulators (i.e., endothelin), inc reased blood viscosity, a nd decreased local vasodilators/regulators (i.e., nitric oxide) (L illy, 1998). Folkow ( 1982) pro posed a “ defens e-rea ction” th eory of incre ased sy mpathetic activ ity in hypert ensio n. Fol kow hypot hesiz ed tha t cert ain in divi duals may undergo defense reactions to conditioned stimuli on a daily basis; without the actual fight-or-flight reaction, and this would in-turn cause marked incr eases in sympathetic a ctivity. I f the conditioned stimuli were continually repe ated, adverse structural adaptive cha nges of the arterioles would occur, thus leading to the fur ther development of sustained hy pertension

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17 (Brondolo, Karlin, Alexander, Borrow, & Schwartz, 1999; Carels et al., 1998; Folkow, 2000; Wright & Angus, 1999). In numerous studies of y oung patients with essential hy pertension, it has been shown that there are increased leve ls of plasma norepinephrine and elevated norepinephrine spillover (Esler, 2000; Grassi et al., 2000; Rahn et al., 1999). I n a study by Ega n, Panis, Hinderliter, Schork, & Julius (1987), mildly hy pertensive young humans had elevated plasma norepinephrine level s and enhanced skeletal muscle vasoconstrictor tone. These findings provide understanding of the hemodynamic pr ofile of early human hypertension, which is cha racterized by increased heart rate, c ardiac output, and renal vascula r resista nce. I ncreas ed sy mpatheti c activit y ha s also bee n shown to b e a fac tor in elderly hy pertension. In a study by Grass i et al., (2000), muscle sympa thetic nerve activity was incre ased in 20 untreated elderly essential hyperte nsion patients compared with age-matched controls. I n addition to subjects with existing hypertension, normotensives with a family history of hype rtension have higher rates of nore pinephrine spillover into arterial plasma than do normotensives without a family history of hypertension. This finding may be a c ontributing factor and provide a link for the late r development of hype rtension. It was also repor ted that patients with accelerated essential hypertension have significantly hig her levels of muscle sy mpathetic nerve activity than do patients with milder hypertension. Th ere have been several pr oposed mechanisms for increases in muscle sy mpathetic nerve activity in essential hypertension. One such proposal is that inc reases in muscle s ymp athetic n erve ac tivity may be rela ted to increased central nervous sy stem sympathetic outflow. Anothe r such hypothesis is that patients with essential hyperte nsion have impaired baroreflex sensitivity (Mark, 1996).

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18 Increased sy mpathetic activity and enhanced reactivity to stress have been reported in patients with both borderline and established hy pertension, and it has been suggested that they play a role in the pa thogenesis of hy pertension. The mechanism for these enhanced responses is unknown; however it has been suggested that epinephrine released from the adrenal medulla during physiologic al stress, is taken up into the sympathetic nerve terminal and later released as a co-transmitter with norepinephrine. The nore pinephri ne that ha s been re leased further stimulate s norepin ephrine releas e th ro ug h i ts ac ti on on th e p re syn ap ti c B -a dr en er gi c r ec ep to rs In a r ec en t s tu dy, hyp ertensiv e subjec ts had a 25 % highe r rate of whole body spillover of norep inephrin e to plasma, c ompared to normote nsive con trols. Ad ditionally the epin ephrine secret ion rate was increased in hy pertensives (215 +/209ng/min) versus normotensives (173 + /115 ng/min). These findings provide evidence the epinephrine may prolong and amplify the sympathetic response s at a time when circulating ephinephrine concentrations are no longer elevated (Rumantir et al., 2000; Stein, Nelson, He, Wood, & Wood, 1997). There have also been studies that demonstrate diff erences in SNS activity a mong subsets of the population. Stein, Lang, Sing h, He, and Wood (2000) reported that healthy, normotensive blac k males (compared to agematched white males) had markedl y in crease d levels o f vascul ar sens itivity to an infu sion of the alpha-a drener gic vasoconstrictor substance, pheny lephrine (Stein et al., 2000). This study concluded that increased sy mpathethetically-media ted vascular tone caused by enhanced vasoconstriction and attenuated vasodilation may play a role in the pa thogenesis of hypertension in blacks. I t has also been reported that obese-normotensive a nd obesehypertensive subjec ts have impaired adrenerg ic and baroreflex function. In a recent study Grassi e t al. (200 0) repor ted that m uscle sy mpathetic nerve a ctivity is signif icantly

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19 increased in lean hy pertensive and overweight normotensive subjects (p = 0.01), compared to lean normotensive control subjects. Additionally obese-normotensive and obese-hype rtensive subjects had impaired baroreflex car diovascular control, as measured by the infusion of vasoac tive drugs (nitroprusside and pheny lephrine) and the response of each substance. This study concluded that the association between obesity and hypertension trig gers a sy mpathetic activation and an impairment in baroreflex control mechanisms (Grassi et al., 2000; Julius, Valentini, & Palatini, 2000). Endothelial Dysfunction The endo thelium is c losest to th e arte rial lume n, in the in timal lay er, and i ntimate with blood flow. In the normal artery the endothelium functions to maintain the integrity of the vessel wall by pe rforming various metabolic and signa ling functions. The endothel ium functi ons to (a) act as a barrie r and pro tect sube ndothelia l space, (b) expre ss antithrombogenic substances (heparin, thrombomodulin, plasminoge n activitators), (c) secret e vaso activ e subs tances that p romot e vaso dilat ion (e ndot heliu m-der ived r elax ingfactor and prostacy clin), and (d) inhibit smooth muscle cell migration and proliferation by secre tion of heparin and endothelium-derived relaxing fa ctor. Atherosclerotic lesions develop within the intimal layer (L illy, 1998; L uscher, 1994). Over the last several y ears, increasing attention has be en paid to a substance secret ed by the endot helium kno wn as End otheliumderived -relaxing -facto r (EDRF ), also known as N itric Oxide (NO). I n addition to its vasod ilatory propert ies, NO is known to inhibit platelet aggregation and a dhesion, monocyte a dherence and chemotaxis, and proliferation of vascular smooth muscle cells. Endothelium-derived nitric oxide, a potent vasodila tor, may be an en dogeno us antiat herog enic fa ctor. I n animal a nd human mo dels, vasodila tion caus ed by the rele ase of e ndotheli um-deriv ed NO is di minished in

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20 atheros clerotic vessels. In a ddition, hy percho lesterol emia inde pendent o f observ able atherosclerosis inhibits endothelium-dependent vasodilation. I n addition to NO, the endothelium also produces potent vasoconstrictor substances including e ndothelin-1. The expression of endothelin-1 is stimulated by f actors including thrombin, angiotensinII epinephrine, and the shear stress of blood flow (Chowdha ry et al., 2000; L illy, 1998; Luscher, 1994). Because of the protective nature of the endothelium, it is important that the integrity of the endothelium be intact. In re sponse to some type of “injury ” to the endothel ial lay er, the e ndotheliu m underg oes a con tinuum of c hange s that adv ersely affect the structural and functional phy siology of the endothelial surface. I njured endothelium demonstrates increased permeability to large molecules and substances under the subendothelial space, reduced a ntithrombotic properties and increased vasoconstriction due to decreased secre tion of prostacy clin and EDRF-NO, and increased smooth muscle cell migration and proliferation due to decr eased secretion of EDRF-NO and platelet-derived growth fac tor (PDGF). Atherosclerosis is a disease of the muscular arteries (e.g., aorta, c oronary a nd cerebral vessels) in which the intimal lay er becomes “injured” and thickened by fatty deposits and f ibrous tissue. Elevated levels of serum cholesterol aggrava te the vessel endothelium integrity and cause changes within the vessel lumen. The earliest visible lesion of atherosclerosis is a fa tty streak cha racterized microscopically by the subendothelial accumulation of large, lipid-lade n “foam cells.” Foam cells are derived from macr ophages and smooth muscle cells (SMC’s). Factor s involved in monocyte migra tion and accumulation in the subendothelial space include increased levels of serum cholesterol, esp ecially low-de nsity lipoproteins (L DLs) and oxidized L DLs w hich enc ourag e the pre sence o f adhesi on molecu les and c hemotac tic

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21 proteins. Once in the subendothelial space, the monocy tes become activated macroph ages a nd relea se mitog ens and c hemoatt ractan ts (includ ing tumor necrosi s factor interle ukins, com plement f ragme nts, PDGF immune c omplexes, s mooth musc le cell growth factors, and monocy te chemo-attractant proteins) that rec ruit additional monocytes and promote SMC g rowth and clot promotion. In advanc ed disease, a fibrous plaque of SMC origin develops in the intimal lay er when there is continual accumulation of monocytes, ly mphocytes, foam c ells, and connective tissue. Complications occur due to weakening of the vessel wall, ulcera tion of the vessel wall, occlusion of vessel lumen, thrombosis and distal embolization (Chalmers, 2000; Lilly 1998; Luscher, 1994; Schwartz, Reidy, & De Blois, 1996). Hy pertens ion proba bly is a risk f actor o f endothe lial dy sfunctio n, as incr eases in sympathetic nervous sy stem activity have been shown to injure vascular endothelium and may increa se the pe rmeabili ty o f the ves sel wall to lipopro teins and other at herog enic factors (Lilly 1998; Toikka et al., 2000). Because endothelin-1 is stimulated by mechani sms that ar e affe cted by increa sed SNS ac tivity and a maj ority of patie nts with hyp ertensio n have c linically increa sed SNS ac tivity it could b e possible that these factor s may influenc e periph eral re sistanc e, and the refore BP. I n addition decre ases in endothelium-derived vasodilating and increa ses in endothelium-derived constricting factors cause an increase in BP and vascular resistance and this may be a risk factor for hyp ertensio n develop ment. I n a rece nt study by Pa rk, Char bonneau and Schi ffrin (2001), endothelial dilatory r esponses to acety lcholine infusion in the brachial artery cor rel ate s wi th th e pr ese nce of e ndo th eli al d ysfu nct io n i n hu man res is tan ce a rte rie s. In this study, endothelial-dependent dilatory responses were found to be similar in large a nd small arteries in hype rtensive patients. This conclusion suggests that endothelial

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22 dysfunction may have a syste mic rather than a local nature in ather osclerosis and hypertension (John & Schmieder 2000; Park et al., 2001). Endotheli al dy sfunctio n, ather oscler osis, and/ or hy perlipide mia may also precipi tate alte rations in the integ rity of the pr otective endothel ium and the reby increa se vasocon strictor substanc es, lead ing to hy perten sion. Hy pothetic ally if a per son had e arly atherogenesis and/or hy percholesterolemia but no hy pertension, he/she may have impaired EDRF-NO function and increase d endothelin-1 stimulation and therefore may have increases in sy stemic BP (Lilly 1998; Park et al., 2001). Baroreceptor function may be modulated by f actors such as prostacy clin, oxygenfree radicals, and factors r eleased from agg regating platelets (Chapleau e t al., 1995). Endotheli al dy sfunctio n and subs equent a ltered r elease of these factor s contrib ute significantly to the de creased barorecepto r sensitivity in hy pertension and atherosclerosis. Dy sfunctional changes in the endothelium may impair baroreceptor function by r educing the stret ch mecha nisms that provide s ignals t o the auto nomic nervous system. Chapleau e t al. (1995) reported that the inhibition of endogenous formation of prostacy clin and increased platelet ag gregation reduce d baroreceptor activity in health y r abbits. Ad ditionally oxy gen fr ee-ra dical g enerat ion (as se en in atherosclerotic lesions and oxidized-LDL ) suppressed baroreceptor ac tivity in the normal carotid sinus (Chapleau et al., 1995). Structural/Functional Theory As mention ed previ ously various structu ral and f unctiona l chang es occur within the vessel wall that may e ncourage the development a nd maintenance of hy pertension. Structural and adaptive changes that occ ur in the vessel wall and cardiovascular sy stem include vascular and left ventricular hy pertrophy arterial stiffness, decreased vesse l

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23 compliance, and atherosclerosis of the cor onary and c arotid arteries. In a study comparing age-matc hed borderline versus normotensive subjects, increa sed carotid and bra chi al i nt im a-m edi a th ick nes s wa s s een in th e bo rde rli ne h yper ten si ve g rou p. In addition, oxidized-LDL was incre ased in the borderline hy pertension group compared with the c ontrol g roup (To ikka et a l., 2000) Inte resting ly, a study of moder ately hyp erchole sterolem ic and hy pertens ive subje cts repo rted tha t sy stolic BP a nd pulse pressures are associated with alterations in incr eased carotid-intimal thickening (Zanchetti et al., 2001). Structural and functional changes that oc cur in the pathophysiolog ical processes of atherosclerosis, SNS overactivation, and endothelial dy sfunction can impair baroreflex function (Chaplea u et al., 1 995), impe de blood flow, inc rease r esistanc e of flow increa se BP, and can encourage a number of advanced adver se complications of hyper tension in cl ud in g t hr om bo si s f or ma ti on s tr ok e, myo ca rd ia l i nf ar ct io n, re na l f ai lu re r et in op at hy, and death. It is interesting to note, how ever, that human vessels can underg o massive accumulations of atherosclerotic plaque without narr owing of the lumen. This may be due to compensatory remodeling of the vessel wall and dilating to pe rmit a normal level of blood flow. In studies of balloon-injured r abbit carotid arteries, researche rs found no narrowing of the vessel lumen despite an inc rease in wall thickness (Schwartz et al., 1996). Increase d sympathetic adre nergic activity can also increase arterial stiffne ss and decrease vessel compliance. I ncreased workload on the hear t induced by hy pertension and/or SNS activity causes hy pertrophy o f the left ventricle and decrease d compliance of the ventricle to properly fill and contract blood. The level of arterial pr essure exerts an important influenc e on the le vel of le ft ventr icular mu scle mass Approxima tely 20% to

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24 35% of variability in L V mass can be predicted from the leve l of 24-hour ambulatory BPs (Devereux, de Simone, Ganau, & Roman, 1994). In summary it is clear that there are many factors that are related to hy pertension developm ent and ma intenanc e. Hy perten sion deve lopment a nd mainte nance is most likely extremely individual and probably a function of a combination of the discussed mechanisms and alterations. Because of t he complex nature of the vasculature, circulatory and neurological sy stems, each of these theories impacts SNS activity and thereby c ould promote hypertension deve lopment and maintenance. For the purposes of this study, the SNS hyperactivity theory of hy pertension developmen t will be ex plored as a po ssible lin k between high BP and high BP recognition. In the SNS hy peractivity the ory of hy pertension, high BP is caused by an abnormally incre ased stimulation of the SNS. The exact mechanism for increased SNS activity in hy pertension is largely unknown, but has been speculated by researchers (Folkow, 1982). As mentioned previously the increase in SNS activity stimulates the releas e of cat echolam ines to af fect spe cific ta rget or gans inc luding th e vascul ar smooth muscle, blood vessels, kidneys, and he art. Stimulation of the SNS causes physiolog ical manifestations, such as racing heart, poun ding chest, increased BP, and dilated pupils. Studies show that there are increased leve ls of plasma norepinephrine and elevate d norepin ephrine spillover in essen tial and b orderlin e hy pertens ion, seen in both younge r and older hy pertensives (Egan et al., 1987; Esler, 2000; Gr assi et al., 2000; Rahn et al., 19 99;). Be cause a ge has been sho wn to be a factor in incre ased SNS a ctivity it would seem plausible that adults of increased ag e or young er borderline hy petensives would have increased SNS output and therefore potentially more manifestations of SNS activity Similarly adults wh o are obe se have been sho wn to have impaired adrene rgic

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25 and baroreflex function (Grassi et al., 2000). Ther efore, obese adults may have physica l signs or symptoms associated w ith BP elevation. Whether or not this activity oc curs only during a high BP e pisode or if it occu rs more c onsistentl y is unknown. It is a lso unknown whether obese or elderly hyperte nsives have an increased recog nition or awareness of high BP or hig h levels of sympa thetic activity. Systolic Hy pertension The majority of per sons with systolic hy pertension are not adequately controlling their BP levels despite persuasive data from c linical trials documenting the benefit of treatme nt (JNC VI 1997, p. 6 ). Sy stolic B P has bee n identifi ed as a ma jor measu re in the assessment of risk in hyper tensive subjects (Lac kland, 1999). Observational epidemiologic studies and randomized controlled trials have demonstrated tha t SBP is an independent and strong predictor of risk of cardiovascular and renal disease (Franklin et al., 2001; He & Whelton, 1999). Recent data from the Sy stolic Hypertension in the Elderly Progra m (SHEP) ha ve indica ted a cl ear ben efit of tr eatment w ith a red uction in total stroke of 36%, and a reduction of 25% and 32% in the c ombined end points of coronar y he art disea se and ca rdiovasc ular dis ease, r especti vely ( Silagy & McNeil, 1992). SBP levels have been shown to covary more with physical sy mptoms than either DBP or he art rate (Penneb aker et al., 1982 ). From a perspec tive of tr aining p atients to recognize high BP episodes, it has been sh own that discrimination of systolic pressures occurs a t a sligh tly f aster pa ce than d iastolic pressur es (Cinci ripini et a l., 1979). It al so may be ea sier for s ubje cts to unde rsta nd th e est imati on ta sk as well as min imize confusion b etween SBP and DBP levels, thereby increasing the rel iability of the S BP estimate. Because of the importance of SBP as a predictor in long-term outcomes and

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26 the ease of conceptualization, it is valuable to solely examine the ability of hy pertensive persons to estimate their SBP levels. Issues Surrounding the T reatment of Hy pertension Overview of Trea tment St atistics in High BP A goal of therapy for patients with hype rtension as defined by the JNC VI report (1997) is to reduce BP to nonhy pertensive levels with minimal to no side effects. According to recent estimates from the A merican Heart Association (AHA), one in four U.S. adult s has hig h BP, but be cause th ere ar e no sy mptoms, ne arly one-thir d of these people do n't eve n know the y ha ve it. The curre nt goal f or BP is to h ave BP c ontrolled to less t han 14 0/90 mm Hg. Howev er, it is est imat ed tha t onl y 26.2% of peopl e with high BP are on antihy pertensive medications but do not have it under control. For a historica l perspec tive, in 19 72, 16% of high BP p atients w ere con trolled to less than 160/95 mm Hg, the goal at the time. A rece nt AHA survey indicated that the control rate for today ’s goal of less than 140/90 mm Hg is 29% (AHA, 2003a) Thus, it would seem that we are making progress, but we have a long way to go. The economic burden of uncontrolled hypertension is immense. For example, researchers estimated the number of cases and costs of myocar dial infarction, stroke, and congestive he art failure for patients achieving BP control versus those not achieving control. F or the U.S. population with hypertension, inadequate BP control was estimated to result in 39,702 cardiova scular events, 8,374 cardiov ascular disease deaths, a nd $964 mil lion in dire ct medica l expenditu res. Within the medic ated popu lation with cardiov ascula r diseas e, the inc rementa l costs of f ailure to attain BP goals reached appr oximately $467 million. These results reflect the importanc e of adequate BP control, in particular, sy stolic BP control, in reducing cardiovascula r

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27 morbidity mortalit y, a nd overa ll health c are expe nditures among p atients w ith hypertension (F lack et al., 2002). Poor a dheren ce to an tihypert ensiv e thera py is a maj or the rapeut ic chal lenge contribu ting to th e lack of adequa te contr ol in more than twothirds of p atients w ith hypertension (Miller e t al., 1997; JNC VI, 1997). Compliance is often defined as implementation (by the patient) of the therapeutic plan that has been established (Anderson et al., 1994). Nearly three-fourths of adults with hy pertension are not controlling their BP to below the recommended 140/90 mmHg (JNC VI, 1997). Noncompliance is a multi-faceted biobehavioral issue that may be related to factors such as econo mics, pas t history perce ption of i llness thr eat, ef fect illn ess has on daily activities or work, presence of sy mptoms associated with the illness, and perception of effica cy of thera py. Patients w ith chron ic illnes ses, espe cially hyp ertensio n that pre sents few rec ognizabl e sy mptoms if a ny, often ha ve diffic ulty prescr ibing me aning to their illness. Therefore, these patients have proble ms complying with their thera peutic plans (Mey er et al. 1985; McL ane et a l., 1995). If pa tients with hyp ertensio n can lea rn to recog nize sy mptoms or f actors th at are a ssociat ed with the ir high B P and lear n to recognize when their BP is high, their com pliance with prescribed therapy and motivation to seek or continue treatment may improve. At the sam e time tha t hy pertens ives ar e having problems with adhe ring to treatment regimens, people throughout the world are beginning to embrac e an emerging trend called “self-manage d care.” Self-manag ed care is a term used to describe the a ct ofmaintaining one’s own health and well-being (Strohecker, 1999). Individuals today are looking to manage their own health by becoming empowered and be ing vigilant healthcare consumers. Beca use of the recommendation by the Healthy People 2010

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28 campaign to improve patients’ awarene ss of their BP levels and to improve the percen tage of people w ho know if their B P level is lo w, norma l, or hig h, it is cle ar that it would be beneficial for patients to have incre ased knowledge of their BP levels and factors associated with their high BP. With this in mind, it makes sense that the major health care organizations and prog rams are encourag ing patients to have increased awareness of BP levels and to use automa tic home BP monitors to assist in the management of hy pertension (AHA, 2003a; Healthy People 2010, 2003; JNC VI, 1997). Educational level has an impact on health and health outcomes, a s educated people have been shown to be healthier and have more improved outcomes to treatments, whereas people of lower soc ioeconom ic status t end to ha ve more a dverse r isk facto rs and wo rse health (Winkleby, Fortmann, & Barrett, 1990). I t seems reasonable that if patients were more aware of their high B P episodes and factors associated with them, they would be more motivated to seek and/or continue treatment (Mey er et al., 1985; McLane e t al., 1995). Ad ditionally learni ng to re cognize high BP m ay provide a means to te ach pati ents to use relaxation, biofeedback, and/or pharmacolog ic therapies as a means of reducing elevate d BP leve ls, there by i mproving treatme nt outcome s. Antihypertensive Medic ations Medications, known as “antihy pertensive medications,” are available to treat chronic high BP. There are various types a nd classes of antihype rtensive medications. Each type of medication works at a different site of ac tion in the body to lower BP. Eac h medication has potential side effects that may occur with use of the medication. Often, antihypertensives a re used alone or in conjunction with other antihy pertensive medications. Because of the complex nature of hy pertension, often two or more drugs or therapies are needed to control BP to a no rmal level. The JNC VI report on Prevention,

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29 Detecti on, Evalu ation and Treatme nt of Hig h BP rec ommends th at a diur etic and /or beta blocker be chose n as initia l therap y f or hy pertens ion, unles s there a re spec ific contraindications or reasons to choose otherwise (JNC VI 1997). Diuretics are a ty pe of medication used to treat hy pertension and a variety of other illnesses that work by a cting to increase urine output, thereby decreasing BP. Diuretics inhibit sodium reabsorption and affect electroly te excretion in a particular nephron segmen t. Diffe rent cla sses of di uretic s are av ailable a nd they are ge nerally classified based on their major site of action within the nephron. De pending on the diuretic class, major sites of action include the proximal tubule, thick ascending limb of the loop of Henle, early distal tubule, and late distal and early collecting tubule. Classes of diuretics include proximal tubule diuretics (Acetazolamide), loop diuretics (Furosemide), thiazide diuretics (Hy drochlorothiazide), potassium-sparing diuretics (Spironolatctone), and osmotic diuretics. Diuretics are g enerally w ell tolerated and side effects are minimal; however, car e should be taken to avoid electroly te imbalances. Diuretics are frequently used alone or in combination with other antihy pertensive medications for the treatment of hy pertension (Smith & Rey nard, 1995). Calcium c hannel bl ockers ( CCBs) a re anoth er ty pe of med ication th at are u sed to treat hy pertens ion. CCBs b lock the m ovement of calc ium into the arterio lar smooth muscle and cardiac cells and may inhibit the mobilization of calcium within these cells. In the treatme nt of hy pertens ion, CCBs a ct as ar teriolar dilators a nd reduc e sy stemic vascular resistance. CCBs are ef fective as monotherapy and in conjunction with other antihy pertens ive medic ations, e special ly b eta-blo ckers a nd centr al sy mpatholy tics (Smith & Reyna rd, 1995).

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30 Beta blockers (BB) ar e also very effective in l owering BP in h ypertension. BBs are com petitive a ntagon ists for no repinep hrine an d epineph rine re ceptor s ites in the heart, bronchio les, and b lood vesse ls in the ske letal mus cles. The mechani sm of BB action is accompl ished by blocking the beta recept ors in the heart, b ronchiol es, and b lood vesse ls in skeletal muscle, and promoting vasodilation and decrea sing BP. BBs decrea se cardiac output, central sympathetic output, pre synaptic be ta receptor inhibition, and inhibition of renin. Different ty pes of BBs are classifie d according to their site of action and selectiv ity o f beta r eceptor sites. Be ta-1 se lective a cting a gents a re sele ctive fo r beta receptor sites in the heart. For example, two ag ents that are relatively cardio-selective include Metoprolol and Atenolol (Smith & Rey nard, 1995). Another type of antihypertensive m edication is the angiotensin-converting enzy me inhibito rs (AI ). AI s are g eneral ly well tole rated a nd the most common ad verse effect is chronic cough. The me chanism of action of AI s is on the Renin-AngiotensinAldosterone System (RAAS). B riefly, the RAAS is a key play er in the regulation of human BP. Renin is an enzy me that is f ound in the kidney and resp onds to a dr op in BP, stimulation of the SNS, or decreased extracellular sodium concentration. Renin is the catalyst for the conversion of angiotensin I to potent, vasoconstricting, angiotensin I I. Angiotensin I is converte d to angiotensin II by an enzy me found in the lung, angiotensinconverting enzy me. The system assists the body in maintaining BP. In hy pertension, wh er e t he re ma y be ab no rm al ly h ig h l ev el s o f S NS ac ti vi ty o r a bn or ma l r en in ac ti vi ty, AIs work to disrupt the conversion of a ngiotensin I to ang iotensin II (Porth, 1998). Typ es of AI s include Captopril Enalap ril, Fos inopril, Ri mipril, Qu inapril, a nd Benze pril (Smith & Reynard, 1995)

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31 Biosituat ional Factors A ssociated w ith High BP Alterations and/or uncompensated increases in SNS activity in hypertensives may cause physic al signs and symptoms. As de scribed, increased SNS activity and hypertension ar e often characterized by an increased heart rate cardiac output, and renal vascula r resista nce. The se effe cts incre ase BP, flush the skin, incr ease fa tigue, i ncreas e heart rate, and a cause a “ pounding or racing” he art (Seeley et al., 1998). The SNS als o promote s numerou s metabo lic effe cts throu ghout the body These effec ts include : enhanc ed metab olic rate of body cells, inc reases in blood g lucose le vels, mobilization of fats to be used as fuels, and increased mental alertne ss via stimulation of the reticular activating sy stem (RAS) of the brain stem. Additionally, inc reased SNS activity may promote smooth muscle cell growth and increase the likelihood of atheros clerotic lesions a nd the dev elopmen t and/or a cceler ation of h ype rtension (Grassi et al., 2000). A number have studies suggest that both normotensives a nd hypertensives ha ve symptoms associated with fluctuations in their B P levels (Dimenas et al., 1989; Pennebaker et al., 1982). I n a study by Pennebaker et al. (1982), y oung, normotensive subjects were e valuate d to see if sym ptoms cor related with fluc tuations in BP. Within subject anal ysis found that 77 % of the subjec ts had at leas t one signifi cant symptom-SBP correl ation. I nteresti ngly the withi n-subje ct corr elation v aried f rom subje ct to subje ct, indicating that different people perce ive different sy mptoms during fluctuations in BP. Despite the individual variations, however, sy mptoms of heavy brea thing, pounding heart, and fast pulse tended to be high for the majority of subjects. I n contrast, another study reported that hy pertensive subjects experienced more emotional distress and

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32 cardia c and re spira tory sympto ms (i .e., s weatin g, flus hing, dry mouth cough ing, dizziness, and dyspnea) (Dimenas e t al., 1989). BP Varia bility BP is labile and normally fluc tuates in response to both behavioral and biosituational factors. These include activity level, posture, emotional state, communic ation pat tern, bod ily f unction, a nd intern al or exter nal envir onment. Pe ople with hypertension display significantly g reater 24-hour variations in mean ar terial pr es su re th an do no rm ot en si ve s ( Ma nc ia D i R ie nz o, & P ar at i, 19 93 ). In o ur la bo ra to ry, for ex ample the r ange of S BP of 1 0 hyperten sive s ubjec ts var ied fr om a mi nimu m range of 19 mmHg to a maximum o f 56 mmHg BP vari ability is influen ced by both biosituational and behavioral factors, presumably through central modulation of autonomic drive to the heart and sy mpathetic blood vessels. This may be due to greater pressor responses to emotional and other behavioral stimuli due to an incre ased central emotional reactivity in essential hy pertensives (Esler, 2000). Factor s such as d ietary intake, g ender, ethnicity alcohol /caffe ine intak e, stres sors, seasonal variations, circadian fluctuations, coc aine and similar drug use, tobacco use, or others may ef fect BP fluctuations (Campbell, McKay Chockalingam, & Fodor, 1994; Gellman et al., 1990). Brondolo et al. (1999) noted similar finding s when they investigated the effects of workda y communication patter ns on physiologic par ameters. It wa s found tha t natura lly o ccurri ng inter persona l interac tions wer e associ ated with increases in SBP and heart rate. Headache Several studies have assessed whether or not the symptom “headac he” was related to BP levels. Kruszewski, Bieniaszewski, Neubause, a nd Krupa-Wojciechowski

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33 (2000) reported that although 30% of stag e 1 and2 hype rtensive subjects (N = 150) experienced headache durin g 24-hour ABPM, h eadache was not associated w ith BP elevations, mean BP levels were not signific antly highe r than those during headache-f ree periods, BP means 1 hour be fore an d 1 hour a fter the headac he were not signi ficantly different, and in the majority of hyperte nsives, the maximal BP values were recorded outside the headache periods. Dimenas et al. ( 1989) similarly reported tha t hypertensive subjects did not complain of headaches, as compare d to other studies which show that headache is more frequent in patients with hy pertension (Bulpitt, Dollery & Carne, 1976). Headache has been spec ulated to be related to increased pre ssure and stretching of the vessels of the dura at the base of the br ain (Seeley e t al., 1998). Mood/Communication Pattern Mood has been reported to be associated with B P. Positive mood accounted for 6% of the within subject variance for sy stolic and diastolic BPs (Gellman et al., 1990). Negat ive mood a ccounte d for 8% o f the wit hin subjec t varian ce for s yst olic and d iastolic BPs. The BPs were gener ally highe r during the positive and negative mood states a nd were lowest during a neutral mood state. Mood was classified into three categories: (a ) neutral mood (i.e., content); (b) negative m ood (i.e., tense, annoy ed, upset, angry ); and (c) posi tive mood ( happy and smiling ). In previous studies, it was rep orted tha t primari ly negative mood was associated with increa ses in BP (Brondolo, Karlin, Alexander, Borrow, & Schwartz, 1999; James, Yee, Harshf ield, Blank, & Pickering, 1986). Communica tion patte rns have also bee n associa ted with in crease s in BP. Brondolo et al., (1999) reported that intera cting with the public, supervisor, or coworker within the prior 15 minutes of BP measurement had an stimulatory effect on BP and cardiov ascular reactiv ity i n normote nsives a nd hy pertens ives. Ele vated B P response s to

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34 positive or negative mood or communication patterns may elicit a cardiovascular response, similar to the defense reaction hy pothesis proposed by Folkow ( 1982). Anger Hostility Stress, a nd Anxiety Durel, Ca rver, Spi tzer, L labre, We intraub, and Saab (1989) e xamined BP levels and dispositional anger and hostility in 13 5 African Americans and Caucasion male a nd female n ormotens ives and u nmedica ted mild to moderat e hy pertens ives. Usin g ABPM, this study revealed that c ognitive anger and statetrait anxiety were strong ly associated with higher SBP and DBP levels at work. I n this study, women showed significa nt positive relationships between hostility, ang er, and anxiety and e levated BP at work. Male subj ects show ed no asso ciation b etwee n ange r measur es and AB PM levels. Shapiro, Goldstein, and Jamner (1996) examined the association between cy nical hostility, anger, de fensiveness, and anxiety on BP in African American and Caucasion college students. This study r eported that high-hostile African Amer ican subjects had higher SBP during the day and at night compared to high or low hostility Caucasion subjects Africa n Americ an subjec ts who sc ored hig h on both a nxiety and defe nsivenes s had higher waking DB P. These studies suggest that there is an assoc iation between anger and hostility and higher BP levels. Additionally, these studies suggest that gender, ethnicity, ty pe of self-report instrument, activity and other personality traits may influence the association (Carels et al., 1998). F actors such as anger and stre ss have been shown to e ffect th e “fig ht or flig ht” resp onse, the reby increa sing ca techola mine rele ase and subsequent SNS effects (Seeley et al., 1998). Environment A stressf ul home en vironmen t can ca use elev ations in B P similar to those see n in the work environment (Blumenthal, Towner, Thy rum, & Seigel, 1995; Carels et al.,

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35 1998). Blumenthal et al. (1995) reported that mar ried women had significantly higher BP levels than unmarried women, but married and unmar ried men had similar pressures. In a study by Schnall et al. (1992), 262 e mployed males we re studied and it was found that socia l support d id not aff ect BP in depend ently but the a ssociatio n of job str ain with DBP was s tronge r for the subjects who had l ow levels of socia l support. Mild hypertensive subjects have also been shown to have grea ter home versus work differences in BP, as compare d to normotensives (Durel et al., 1989; Gellman et al., 1990). Additionally, Durel et a l. (1989) found that there was a significa nt correlation among Caucasion and African Amer ican women between work relate d hostility and anger and BP. T his finding may be rela ted to inc reased or aug mented SN S activity in response to stressors seen in patients with hy pertension. Work characteristics, such as perce ived psycholog ical job demands and decision latitude, may contribute to workrelated stress. Job strain is defined as “a combination of high psycholog ical demands together with low decision latitude.” At lea st 12 studies have examined job strain and ABPM in a naturalistic environment (Carels e t al., 1998). Theorell, Perski, Akerstedt, Sigala, Ahlberg -Hulten, and Svensson (1988) examined 73 normotens ive men and wo men in six different occup ations and found increas ed SBP during work hours among those reporting high job strain, relative to those reporting low job strain. Other studies examined hypert ensive and normotensive subjects and discovered that job strain was related to increa sed SBP and DBP at work, home, and during sleep (Schnall, Schwartz, La ndsbergis, Warren, & Pickering 1992; Vrijkotte, van Dooren, & de Geus, 2000). Elevations of B P at home, work, or stressful job environm ents may be rela ted to ac tivation o f the SNS a nd the “f ight or f light” r esponse (Brondolo et al., 1999).

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36 Posture Various postural positions effect BP levels. For example, in a study performed on 87 normotensive and 44 hype rtensive subjects, the effects of posture on B P were examined It was found that 33% to 47% of t he withinsubject vari ance in SBP an d DBP could be explained by cha nges in posture. As subjects in this study went from lying down to sitting to standing, their BP sy stematically incr eased (Gellman et al., 1990). The barore flex mechan ism i s a pos sibl e physiol ogical mechan ism f or chan ges seen throu gh the eff ects of p osture. T his refle x is initiate d by pressur e-sensi tive rec eptors, l ocated i n the walls of the large arteries of the neck and thoracic reg ions, carotid artery and the aortic arch. The barorece ptors respond rapidly to acute drops or elevations in BP. Upon standing, gravitational forces push blood downw ard and blood flow rapidly decreases from the h ead and neck re gions. B aroref lex stretc h recep tors sens e chang es in pressure/stretch and react, causing a rapid increase in action potentials toward the cardioregulatory center in the medulla to increase pressur e. Phys ical Act ivity BP levels are profoundly influenced by physical activity levels. Acute physic al activity and/or exercise inc rease BP levels (Carels et al., 1998). O ver an extended period of habitual exercise, subjects have improved their car diorespiratory e ndurance and eventually lower resting BP and control hy pertension (Jessup, Lowenthal, Pollock, & Tu rn er 1 99 8) P hys ic al ac ti vi ty a cu te ly r ai se s B P d ue to th e i nc re as ed ae ro bi c a ct iv it y, which increases oxyg en demand, blood flow, cardiac output, and BP (See ley et al., 1998).

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37 Lifesty le Factors: Smoking, Caffeine, and Sodium I ntake Laboratory studies suggest that smoking a cig arette results in an immediate and marked increase in BP. I n addition, studies have shown that ABP is higher throughout the day in smokers compa red to nonsmokers (Groppelli, Giorgi, Omboni, Parati, & Mancia, 1992), particularly for those smokers who have consumed caff einated beverages (Narkiewicz et al., 1995). Smokers also tend to have much more B P variability than do nonsmokers. Caffeine increases BP level s and potentiates cardiovascular and neuroendocrine effects of stre ss in both habitual and light consumers (La ne, Adcock, Williams, & Kuhn, 199 0). Hy pertens ive subje cts, in co ntrast to n ormotens ives, displayed signific ant increases in SBP and DBP after c onsumption of coffee. This is due to the vasoconstricive properties of the drug caffeine (Hartely et al., 2000; Rakic, Burke, & Beilin, 1999). A review of literature on sodium intake and BP reported that higher intake of sodium is associated with higher BP levels. This response ma y be due to the physiological wa ter-conserving effec ts of sodium, thereby incr easing blood volume and BP (Chobanian & Hill, 2000). Typ e A Perso nality The Type A individual is characterized by feelings of time urgency impatience, hostility, agg ressiveness, and competitiveness. The Ty pe A personality ha s been associa ted with in crease d risk of c oronary heart di sease. T ype A individua ls exhibit higher cardiov ascular response s in the na tural e nvironme nt, but only under ce rtain circumstances (i.e., stressful situation, job strain). Ty pe A individuals have higher heart rates and BP levels and grea ter BP variability than Type B individuals (Carel et al., 1998; Steptoe, 2000). This response is most likely re lated to Type A individuals having increased reactivity of the SNS and therefore continual “defe nse reactions.”

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38 In summary BP is affected by numerous biological, situational, and behavioral factors. Res earch studies have shown rel ationship s between the se factors and BP variablity (B rondolo et al., 1999; Carels et al., 1988; Durel et al., 1989; Gellman et al., 1990; James et al., 1986; Lane et al., 1990; Theore ll et al., 1988). Despite the growing research literature on relationships betwee n biosituational or behavioral factors and higher BP levels, it is widely held that high BP is a relatively asymptomatic event. BP Awareness and Estimation Discrimination of physiologica l processes has been of interest to resea rchers for some time. Laboratory procedures have been de veloped to assess a subject’s accuracy of physiological pa rameters. Discrimination of heart rate, B P, skeletal muscle tension, and blood glucose (Barr et al., 1988; Gre enstadt et al., 1986) has been reported. Discrimination of BP by hy pertensive patients is of interest to researche rs and clinicians because hyp ertensio n is consid ered a r elative ly “ silent” di sease in which imme diate sensory conse quences are not available to the individual. The deve lopment of procedures that facilitate detection of BP change s may be use ful in the management of hy pertension. According to C inciripin i, Epstei n, and Martin (1979), tech niques used to facilit ate BP discrimination should utilize procedures that are easily applied in the natural environment and not too disruptive to the patient’s lifesty le. In the clinical setting, patients with hig h BP often report that they can identify when the ir BP is hig her then normal. O ften the se patie nts are c orrect in their a warene ss and it has led them to receive treatment based on their physiological mea surements after subjective reporting. Patients often provide clues to their hig h BP through such statements as, “ I just don’t feel rig ht,” “I fee l pulsing or throbbing in my he ad,” or “I feel hot and tense .” While it s eems cle ar that some peop le are b etter at sensing high BP,

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39 the question remains as to why some pe ople are able to do this while others are not. One potential hypothesis is that patients with high B P have a higher SNS output and are aware of symptoms relating to this phy siologic phenomenon. While there is no direct link between BP estimation and SNS activity, there are studies that show elevated SNS neurotransmitters in patients with high BP (Rahn et al., 1999). Individuals, both normotensive and hy pertensive, may estimate their BP levels by using both internal sensory and external situational information (Barr et al., 1988). Estimations and beliefs about BP levels may or may not be ac curate, but they are important because people act upon them. I n fact, Pennebaker et al. (1982) sug gest that variatio ns in BP ar e corre lated wit h differ ent sy mptoms and that a pe rson can monitor his or her BP by monitoring symptoms. I n studies where both normotensive and hyp ertensiv e people were a sked to es timate th eir BP le vels, est imated B P was stron gly associated with symptoms and moods (Ba umann & Leventhal, 1985) and with feelings of physical tensene ss and physical ac tivity (Fahr enberg et al., 1995). Several studies tested whether or not people can a ccurately estimate their BP. The findings have been fraug ht with much speculation and conflicting results (Bar r et al., 1988; Baumann & Le venthal, 1985; Brondolo et al., 1999; Cinciripini et al., 1979; Fahrenberg et al., 1995; Gre enstadt et al., 1986; Luborsky et al., 1976). An important variable among these studies was the addition of a feedback intervention. Clinical Relevance of BP Awareness and Estimation The question of what is a good level of ac curacy in estimating BP has not necessarily been answered with a definitive number. How ever, several studies examine BP and coronary event ou tcomes. For ex ample, stu dies assess ing the effects o f BP reducti on and out comes fo und sign ificant associa tions betw een rel atively small

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40 reductions in usual BP (5, 7.5, and 10 mmHg) and 34%, 46%, a nd 56% less stoke and at least 21%, 29%, 37% less coronary heart disease (MacMahon et al., 1990) Therefore, even incremental changes or awareness in BP may be a good outcome of BP estimation resear ch. Addit ionally severa l studies ha ve found that awa reness o f BP leve l is a predictor of health outcomes in patients with hy pertension (Asai et al., 2001; Hy man & Pavlik, 200 1). Ther efore, it is clinic ally importan t for pati ents to be more awa re of the ir health sta tus and B P. BP Estimation Without a Feedback Interv ention Only two studies address the que stion “Can people estimate their BP without any typ e of fee dback or training interve ntion?” Tab le 2-1 de scribes the sample descrip tions, methods, and findings of each study In both studies, subjects were g enerally a nd statistically inaccura te in estimating their BP correctly Interestingly perceived BP was associated with symptoms and moods, rathe r than with actual BP in a majority of subjects. Although some participants were better estimators than others, no differences among subject characteristics wer e found (Baumann & L eventhal, 1985; Fahrenberg e t al., 1995). Fahrenberg and his collea gues (1995) assessed whether subjects’ estimation of BP was related to various self-assessments (f eeling tense, phy sical activity, fee ling nervous) or actual BP or heart ra te. This research inquiry involved 51 hypertensive (defined by WHO criteria) male subjects, age s 22 to 60 years and a second group of 30 volunteer hypotensive or normotensive student subjects ages 20 to 28 y ears. The hyp ertensiv e grou p was enr olled in a rehabi litation c enter a nd was simu ltaneous ly receiving exercise therapy health education, group therapy and relaxation training. The hypertensive g roup participated in 3 day s of psycholog ical and physiolog ic monitoring.

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41 The first 2 days we re consecutive and the 3rd day was approximately 14 day s after the first days. The nor motensive/ hypotensive g roup participated using a SpaceL abs 90207 ambulatory B P monitor (SpaceLabs, I nc, Redmond, WA). Personality asse ssments and self-evaluations of phy sical symptoms were also collected. A programmable pocke t compu ter (C asio P B 1000 ) was u sed by bot h group s to es tima te the ir SBP (in mm Hg) and record self-report items. Table 2-1. Research studies: BP estimation without feedback Authors Sample description Methods Findi ngs Fahren berg, Franck, Baas, & Jost (1995) 51 hypertensive males & 30 normoten sive male and fema le students. BP measured every 30 minutes a bout 25 time s; concurrent diary of estimated BP, physic al activity, & subjective states. Estimated BP & actual SBP were poorly correl ated; Selfratin gs tense & activity were signific antly related to estimate d BP. Baumann & Leventhal (1985) 20 hypertensive & 24 normotensive male & f emale subjects BP measured 2 times per day for 10 days. BP estimate d categ orically (same, higher, or lower than usual) & assessed moods/ sy mptoms. Estimated BP & actual SBP were poorly correlated; 6 out of 41 subjects had significant correlations betwee n SBP & estimate d BP; Estimated BP related to sy mptoms. Within-subject correlations revealed that estimated BP was not re lated to actual BP. More extended experience in BP estimation tasks did not enhance the cor relation coefficients in hypertensive pat ients (day 2, r = 0.32 an d day 3, r = 0.27). Est imated SBP was related to self-reports of sy mptoms and activity. Stepwise reg ression indicated that self-ra tings of tensene ss and hea rt rate p redict ed estima ted SBP in h ype rtensive patients; however, actual SBP was not related to estimated SB P in any of the reg ression models.

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42 It is unclear whether subjects had variability in their estimations or actual BP and how oft en t hei r BP was hi ghe r th an 1 40 m mHg (no rma l BP cut -of f po in t) ( JN C VI, 1997). This issue is important because there may be no physiologica l cues for the patient to refer to if there are not any higher than normal reading s. Differences among the hypertensive a nd student groups may have occurred beca use of differing settings (i.e., rehabilitation center versus naturalistic environment) a nd treatments (i.e., rehabilitation environm ent vers us no addit ional tra ining) Althoug h the find ings pre sent insig ht into awareness of BP, it is premature to ge neralize these findings to cohorts of either hypertensive or normotensive subjects because of the presenc e of potential confounding variables and differences among groups (e.g., g eographic, treatment, instrument). Baumann and Le venthal (1985) performed a similar study that assessed three main research questions: (a) whether moods or symptoms are associate d with BP in the work setting, (b) whether people ar e accurate in assessing the ir BP levels, and (c) whe ther the re are disposition al facto rs that a re assoc iated wit h people’ s ability to predict elevated BP. They used a convenience sample and included a heterogeneous group o f 44 insur ance co mpany employ ees (20 subjects with hy pertens ion, 24 sub jects without hypertension). The subjec ts’ actual BP levels were measure d two times per day (in th e morn ing and in th e after noon) for 10 d ays. The ac tual B Ps wer e measu red us ing a mercur y c olumn Ba umanonome ter and a single tube steth oscope. There w ere six experimenters who were trained as scree ner technicians by the Wisconsin Heart Associat ion. Collect ed data inc luded the f ollowing : • Actual BP. • Estimated BP level (i.e., c ategor ical va riablehigher than usua l, same a s usual, lower than usual).

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43 • Moods/symptoms (i.e., 10-item mood list and a 12-item sy mptom list regarding how the subject felt within the last hour). • Personality measure s (i.e., self-esteem scale, privatebody consciousness sca le). • BP estimation confidence rating (i.e., 1 = guess, 2 = confident, 3 = very confident). • Initial interview questionnaire and poststudy questionnaire (i.e., questions pertaining to whether subjects can tell if B P is up or down). Baumann and Le venthal (1985) found that only 6 out of 41 (15%) correlations of actual to predicted BP were statistically significant (p = 0.01) with an accur acy correlation “r” of gre ater than 0.14. It wa s not clear how the researcher s computed the numeric al estima ted BP le vels, as e stimated BP in this st udy was a ca tegori cal var iable (i.e., hi gher, same, or lower). The resu lts also sh ow that B P predict ions and sy mptoms were correlated more strong ly (56% at p = 0.05) than actual BP to predicted BP (15% at p = 0.05) Inte resting ly, subjects claimed to be fai rly confide nt in the B P predict ions, with a mean confidence rating of 2.38 out of a possible 3. In summary both studies found that people are gener ally inaccur ate in estimating their BP. Additionally, both studies repor ted that people estimate their BP higher when they are experiencing sy mptoms that they associate w ith high BP. These studies provide a glimps e into the question o f whethe r people are aw are of t heir BP. BP Estimation With a Feedback Interve ntion Other stu dies have been und ertake n to answe r the que stions “Ar e people accura te in judging their SBP?” and “Does feedback improve estimation?” Table 2-2 describes studies that examined BP estimation and provided subjects some type of feedback intervention.

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44 Table 2-2. Research studies: BP estimation with feedback Author Sample Design/methods Findi ngs Lub or sk y, McClintock, & Bortnichak (1976) 21 male & female subjects, 9 of those taking antihypertension medications Five sessions of feedback/no feedback, 2 assigned comparison groups. Feedback group improved after feedback from 11.5 mmHg to 7.4 mmHg. Accuracy was maintained over 5 phases. Cinciripr ini, Epstein, & Martin (1979) 18 normotensive subjects BP meas ured twic e daily for 20 day s/4 weeks. 2 randomly a ssigned groups received either feedba ck or no-feedback. Feedback group accuracy improved & effects were maint ained throu gh condition s. Greens tadt, Shapiro, & Whitehead (1986) 72 normotensive subjects Experiment #1: 4 sessions (1 pre, 1 post, 2 feedback training). Experime nt #2: 2 sessions (1 feedback, 1 no feedback). Experime nt #3: sing le session of feedback of DBP Feedback improved estimation of SBP. Initi al feed back did not improve subsequent accuracy of BP estimations. Feedback improved estimatio n of DBP. Barr, Pennebaker, Watson (1988) 64 normotensive male & f emale subjects Experime ntal desig n with random assignment to 4 treatment groups (no feedback, internal feedback, external feedback, or biosituational feedback). Estimate d SBP & reported sy mptoms. 43.8% of s ubjects had significant correlations between actual & estimated SBP after the feedback compared with 26.6% before feedba ck trai ning. Brondolo, Rosen, Kostis, & Schwart z (1999) 54 mi ld lyhypertensive males Estimated BP & recorded moods/symptoms an average of 7.5 times. Subjects provided prior BP feedback. Significant withinperson association of actua l to predict ed BP.

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45 Luborsky et al. (1976) performed a study on 21 subjects (16 normotensives, 5 stage-1 hy pertensives) to assess the ability of people to estimate their SBP after being given feedback of daily BP information. In this study mean raw error (absolute value) scores for numerical SBP were compa red between baseline and fe edback groups. Feedba ck, in the form of p roviding the subje ct their m ean pre vious SBP r eading s, improved the estima tion of SB P by 5 mmHg. T he author s conclud ed that th e key to becoming more a ccurate in est imating SBP i s learning your indiv idual range of BP levels. Cinciripin i and coll eague s (1979) studied 18 normoten sive stude nt volunte ers to assess the effects of providing BP fe edback on the ability to discriminate systolic and diastolic BP. The subjects were randomly assigned to two groups, one that provided feedback and one that provided fee dback after an extended baseline per iod. Group 1 consisted of feedback (i.e., the mean of tw o BP readings for that session) that was provided to the subjects for five day s in a multiple baseline fashion. The procedure began with an initial screening for BP variability, 5 da ys of baseline ( no feedback), 5 days of fe edback, and 10 day s postbaseline (no feedback). Group 2 subjec ts had an extended b aseline period f ollowed b y a feedba ck condit ion. The s ubjects w ere ask ed to estimate their sy stolic and diastolic BP leve ls twice a day for 20 co nsecutiv e day s prior to measuring them using a mercury sphygmo manometer. This study eva luated the difference between estimated a nd actual BP using the absolute deviation in mmHg betwee n the estim ate and a ctual mea n daily BP. Those in group 1 improve d their a bility to estimate their actual BP after the sequential implementation of f eedback. The mean SBP daily deviatio n score a t baseline for gr oup 1 was 9 .6 mmHg a nd after feedba ck it declined to 5.9 mmHg. This improvement continued after the fe edback sessions and was

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46 maintained during the no feedback, postba seline period. Those in group 2 showed no statistica lly s ignific ant improv ement dur ing the extended b aseline period; h owever their accuracy level improved after the addition of feedba ck during the last week of training. These subjects improved from a mean SBP daily deviation score of 9.0 mmHg to a score of 3.6 mmHg after feedbac k was provided (Cinciripini et al., 1979). Greenstadt and colleagues (1986) performed an experimental study on 72 healthy normotensive volunteers to assess the benefit of discrimination training on the a bility of normotensive subjects to detect changing levels of their own BP. Overall, this study concluded t hat normot ensive subj ects have relati vely no awareness of sm all BP variations but that feedback in th e form of “knowl edge of results ” improves BP discrimination. Barr et al. (1988) studied 64 normotensive subjects for 3 sessions (3 months apart) to assess the effects of internal a nd environmental feedback on SBP estimation. This study was unique in that it utilized biosituational feedback methods. Biosituational feedba ck involve s providin g feed back to t he patie nt rega rding in ternal ( e.g., a ctual BP symptoms, moods) and external (e.g ., environment, posture, diet) factors that occur du ri ng th e m ea su re me nt of BP (B ar r e t a l. 1 98 8) In th e f ee db ac k p ha se of th e s tu dy, subjects were randomly assigned to one of four gr oups: no feedback, sy mptoms/mood feedback, situational/activity feedback, or biosituational feedback ( a combination of the previous two feedback ty pes). Approximately 71.4% of the subjects in the biosituational feedback group had sig nificant accuracy correlations, compared with 31.3% in the symptoms/moods group, 44.4% in the situational g roup, and 31.3% in the control (no feedback) group.

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47 Brondolo et al (1999) prov ided 54 mil dly-hypertensive subjects with thei r SBP range after a base line period. This study found sig nificant within-subject associations of actual to predict ed SBP (p = 0.002) a nd DBP ( p = 0.02) in 54 mildly hyp ertensiv e male subjects The aut hors also took into c onsider ation fa ctors tha t may influenc e judgme nts about BP estimation including home BP monitoring and use of medica tions. The fi nd in gs in di ca te th at g iv en so me in fo rm at io n a bo ut th ei r p re vi ou s B P, su bj ec ts di sp la y a limited but reliable relationship between their actual and estimated SBP. In su mmary five stu dies that h ave pro vided fe edback to people to improve their ability to estimate their BP have show n an improvement in BP discrimination after feedba ck. Diff erent ty pes of fe edback have be en used to assist subj ects in le arning to recognize sy mptoms, situations, and factors that are associated with their BP levels. Providing normotensive (Barr et al., 1988; Cinciripini et al., 1979; Gree nstadt et al., 1986) and hyper tensive subjects (Brondolo et al., 1999; L uborsky et al., 1976) knowledge of their actual BP levels ha s been somewhat successful in improving the accuracy of BP estimation. Discussion of BP Estimation Studies Among the feedb ack intervent ion-type studies, all showed an improvemen t in BP discrimination after feedback (Ba rr et al., 1988; Brondolo et al., 1999; Cinciripini et al., 1979; Gre enstadt e t al., 1986 ; Lubo rsky et al., 1 976). I n contra st, both stu dies that d id not provid e feedb ack fai led to show associa tions betw een act ual and e stimated B P levels (Baumann & L eventhal, 1985; Fahrenberg et al., 1995). However, both studies found relationships between estimated BP and self-re ports of physical sy mptoms and subjective state. Limitations for gener alizability include the use of normotensive, y oung-student, or convenience s amples; th e amount and frequency of the feedback in tervention s and/or BP

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48 estimations; and the lack of application to real-life situations and circumstance s of America n hy pertens ive patie nts. I f patien ts can be trained to recog nize when their BP i s elevated, they may be ca ndidates for some further intervention (e.g ., biofeedback training ) to help c ontrol the ir BP. How ever, m ore res earch i s needed to conclu sively state tha t patients with hy pertens ion are e ither ac curate or inacc urate in estimatin g their SBP levels. This review of research provides suppor t for using feedback methods to improve the abilit y to estimate BP and sug gests th at BP aw arenes s may be improv ed in some people using feedback methods. The limited number of studies studying hy pertensive persons w ith high B P sugge sts that mor e rese arch is n eeded to further assess th e effe cts of BP aw arenes s feedba ck train ing amon g this g roup. Res earch i s needed to evalua te clinical outcomes of BP awareness training such as BP control, patient motivation and compliance, cost-effectiveness, and morb idity and mortality Over the past several y ears, changes have occurred in health care that have made patients more than mere passive participants of their he althcare. Patients are much more willing and able to learn more about their hea lth and well-being than previous generations (Strohecker, 1999). Te aching people about their BP and B P patterns is an effec tive way to improve health of patient s and empo wer peo ple with hy pertens ion to have mor e contro l over the ir own lif e and he alth (He althy People 20 10, 2003) This review o f litera ture sug gests th at BP fe edbac k interve ntions may be an ef fective means to teach people how to learn more about their B P patterns and when their BP is elevated. While this r esearc h is promisi ng, more inquiry is neede d to decid e if trai ning pa tients with hy pertens ion can im prove the ir awar eness of their hig h BP episo des and if this training will ultima tely improve h ealthca re outc omes.

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49 Educational Level a nd Health Disparities Major disparities exist among population groups, with a disproportionate burden of death and disab ility from ca rdiovasc ular dis ease in m inority and lowe r socioe conomic populations. Health disparities are defined as differ ences in the incidence, prevalence mortality, and burden of dise ases and other adverse hea lth conditions that exist among specific population groups in the United States. Several re search studies have reported that hig her educ ated peo ple tend t o be hea lthier an d have imp roved ou tcomes to treatme nts, wher eas peop le of lowe r socioe conomic s tatus tend to have mo re adve rse risk factors and poorer health (My llykanga s, Pekkanen, Haukkala, Vahtera, & Salomaa, 1995; Winkleby et al., 19 90; Winkleb y, Ja tulis, Fr ank, & F ortmann, 1992). F or example data from the N HANES I II study showed th at ther e were highly signific ant diffe rences in BP, body mass index (BMI ), and physica l inactivity for both Afr icanand Mexican-American women compared to white women when educa tional level and ethnicity we re adjusted for (Winkleby, Kre mer, Ahn, & Varady 1998). Disparities also exist in the prevalence of risk fa ctors fo r cardi ovascula r diseas e. L ower ed ucated p ersons a nd racia l and ethn ic minorities have higher rates of hy pertension, BMI, phy sical inactivity, and non-HD L chole stero l, ten d to d evelo p hyperten sion at an ear lier a ge, and are les s lik ely to und ergo treatment to control their high BP (NI H Online, 2003). In a study by Goldman and Smith (2002 ) differ ences in treatme nt adher ence by educati on level a re examine d in patients w ith HI V and dia betes. I t was fou nd that pa tients with higher socioec onomic st atu s an d hi ghe r ed uca ti ona l l eve ls had imp rov ed t rea tm ent adh ere nce and out com es. In this study, the more-educa ted patients were more likely to adhere to therapy and have better self-reported gene ral health. The less-educated patients we re more likely to switch treat ments whic h led t o wors ening ge neral h ealth The au thors assert that t he large

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50 differences in health outcomes exist, not solely because of poor access to car e or poor health behaviors, but because of differe nces in educational level (Goldman & Smith, 2002). Ambulatory B P Monitoring Ambulatory BP monitoring ( ABPM) is a naturalistic BP measurement technique that has been evolving over the past 30 y ears. It is a method that allows a clinician, patient or researcher to monitor multiple BP reading s over a 24to 48-hour period. These devices can measure B P over time and introduce minimal intrusion into the person’s daily routine. A BPM is used clinically to asse ss and diagnose ty pes of hypertension, eva luate pharmacologic and/or nonphar macologic therapies, and monitor resistant and/or borderline hy pertension. Ambulator y B P monitoring has now b ecome a n establis hed rese arch too l in clinical trials. The use of ABPM decrease s threats to external validity and the potential “white c oat” ef fect of observe rs on phy siologi cal and p syc hologic al respo nses. Oscillometric monitors measure SBP, mean arterial pressur e (MAP), and heart rate (HR), from which DBP pulse pres sure (PP), a nd average 24-hour BP diurnal ch anges, BP Load (perce ntage of sy stolic and diastolic readings grea ter than 140 and 90 mmHg during the day and g reater than 120 and 90 mmHg during the night), and BP variability (the standard deviation of the average 24-hour day time and nighttime measures) can be calculated. Ambulatory BP measurements correlate with the extent of targ et organ damage or cardiovascular risk. For example, Verdecchia (2000) r eported that ambulatory SBP, DBP, and PP were independently and directly associated with cardiovascular risk. While the us e of the A BPM is mini mally intrusive to the per son, it may pose comfort issues such as annoy ance from the beeping sound, we ight of the ABPM device,

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51 and bulkiness of the device. Over the past sever al year s, improvements have been made to the devices to make them more “user friendly ” and comfortable for subjects to wear for longer periods of time. Adherenc e has been shown to be enhanced f ollowing empathetic discussion and demonstration of the device. The saf ety of AB PM techniques have been established and complications are r are (NHBPEP-ABPM, 1992). A typical, fully -automatic ABPM device is battery -driven and consists of an arm cuff that can be progra mmed to inflate automatically throughout a 24to 48-hour period. BP is determined in the arm by detection of (a) Korotkoff sounds by one or two piezoelectric microphones under the cuff ( ausculatory me thod) and (b) oscillations transmitted from the brachial artery to the cuff (oscillometric method). The Spacelabs 90207 ABPM device (Spacelabs, I nc, Redmond, WA) measures BP using the oscillometric technique. Auscultatory and oscillometric techniques have not been rigorously compared t o each other to see if one is m ore preferable fo r ambulator y BP monitoring. However, the auscultatory technique is more sensitive to environmental and distracting noises, such as automobiles and large machinery. O scillometric techniques detect systolic and mea n BP and use algorithms to calculate diastolic BP. This may be a we ak ne ss as th es e a lg or it hm s a re no t a pp ro pr ia te fo r a ll su bj ec ts A dd it io na ll y, oscillometric methods are affected by muscle artifacts and tremors ge nerated beneath the cuff. To avoid inva lid or err oneous re ading s, the dev ice shoul d be cali brated p roperly and the cuff should be fit to the subject prior to use. I n short, ABPM is a mature and clini cally app ropri ate me thod for ob taini ng mult iple, natur alist ic amb ulato ry BP readi ngs over a period of 24to 48-hours (NHBPEP-A BPM, 1992).

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52 Summary In summary hypertension, spec ifically hig h SBP, continues to be a major predictor of morbidity a nd mortality of people in the U nited States and worldwide. As many as 50 million American pe ople are estimated to have hy pertension (AHA, 2003a). Isolated sy stolic hypertension is prevale nt among the elderly and people greater than 50 years of age (Franklin et al., 2001). Curre nt diagnostic and treatment modalities have been wrought with difficulties due to a varie ty of phy siologic, psycholog ic, socioeconomic, and practical factors. Curre nt research sugg ests that the sympathetic ner vous system play s a major role in the development and/or maintenance of hypertension (Rumantir et al., 2000). Activation of the SNS leads to a documented psy chophy siologic al “fig ht or flig ht” resp onse and associa ted manif estations It is unknown whether high BP is associated with sy mptoms; however the majority of c urrent knowledge suggests that it is an asy mptomatic phenomenon. Despite the overwhelming support that hypertension is an asy mptomatic disease, studies using BP and biosituational feedback have sh own that peo ple can be train ed to become m ore aware of thei r BP levels. It is unknown whether the combina tion of ambulatory BP methods and biosituati onal self -aware ness tra ining imp roves sub jects’ a bility to recog nize when their BP is elevated. Due to the recent surg e of knowledge reg arding the sy mpathetic nervous sys tem’s con nection w ith hy pertens ion, it se ems likely that some p eople, if not all pe op le c ou ld be tr ai ne d t o b ec om e m or e a wa re of th e i nc re as ed SN S a ct iv it y.

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53 CHAPTER 3 PROCEDURES AND METHODS The purpose of this research was to de termine if subjects with hyper tension could improve their estimation of their SBP after an ambulatory BP feedback and biosituational self-awareness training interve ntion. Resear ch Desi gn A prospective cohort, repeated mea sures, pretest/posttest design was employ ed for this study. A repea ted measures design allows subjects to serve a s their own control and within -subjec t differ ences to be analy zed. The d esign, a naly sis grou pings, a nd data measured are graphic ally display ed in Table 3-1. Populatio n and Samp le The population under investigation was adult hy pertensive persons, aged 21 to 65, in the northern Florida area. Subject rec ruitment was done through both flier advertising and BP sc reening The inve stigato r offer ed BP sc reening over the course o f a 12-mo nth period at various locations. Before BP wa s measured, potential subjects were told that they would be off ered the opportunity to ta ke part in a research study if they qualified. BP w as m eas ure d t wic e 2 m in ut es a par t af ter th e su bj ect sat qui etl y for 3 t o 5 m in ut es. If the BP measurements differed by more than 5 mmHg, an additional BP measurement was taken. The initial BP screening was o btained by ave raging the two BP reading s that agree d within 5 mm Hg. Subje cts who me t the inclu sion and no t the exclus ion crite ria were a sked to pa rticipat e in the stu dy. Every attempt to include d iverse p articipa nts

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54 Table 3-1. Description of design, analy sis groupings, and data measure d Group Hy pothesi s (H) Pretraining Training Posttraining Adult hypertensives (total sample) H 1 ASBP, ESB P, mean AD ASBP, ESB P ASBP, ESB P, mean AD Adult hypertensives college educated H 2, H 3 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Adult hypertensives noncollegeeducated H 2, H 3 ASBP, ESB P, mean AD ASBP, ESB P ASBP, ESB P, mean AD Adult hypertensives BMI < 30 H 4 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Adult hypertensives BMI $ 30 H 4 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Adult hypertensives male H 5 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Adult hypertensives female H 5 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Hypertensive s < 48 years of age H 6 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Hy pertens ives $ 48 years of age H 6 ASBP, ESB P, MI ASBP, ESB P ASBP, ESB P, MI Antihypertensive medication nonusers H 7 ASBP, ESBP ASBP, ESB P ASBP, ESBP Antihypertensive medication Users H 7 ASBP, ESBP ASBP, ESB P ASBP, ESBP Note: ASBP represents actual SBP, ESBP represe nts estimated SBP, mean AD repres ents mea n absolute differe nce, a nd MI repres ents mea n improve ment. (i.e., gender, race, soc ioeconomic, age, and ethnicity ) was made. To determine the sample size, it was estimated that subjects could improve their estimation of SBP by decreasing the differe nce by ha lf. For example, if the mean difference between the actual and es tima ted S BP was 10 mm Hg on da y 1, this d iffere nce wou ld dro p to 5 mmHg. Assuming that the deviation of the difference was 4.0 mmHg, setting an alpha of 0.05, and using a 2-tailed test, 8 subjects would be require d to achieve at least 80% power. Recogn izing tha t subjects may not be abl e to impro ve their estimatio n this much with only a 2-day training period, a second determination of sa mple size was completed based on an improvement of 2 mmHg, the smallest effect that would be important to detect.

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55 Again, if on day 1 the mean difference betwe en the actual and estimated SBP was 10 mmHg and the mean difference on day 4 wa s 8 mmHg, this would constitute an improvement of 2 mmHg. Assuming a standard devia tion of the difference to be 4.0 mmHg, setting an alpha of 0.05, and using a 2-tailed test, 34 subjects would be required to achie ve at lea st 80% pow er. Rec ognizing that these are est imates an d there a re no dat a suggesting the appropria te effect size to use, 42 subjects were rec ruited for study to allow for attrition and incomplete data. To ensure that subjects would have adequate va riability to be able to detec t differe nces, we randomly selecte d ambula tory BP data f rom 10 hy pertens ive subje cts in Dr. Yucha's researc h study. For these 10 subjects, the average day time range in SBP was 33.2 mmHg, ranging from a minimum of 19 to a ma ximum of 56 mmHg. Therefore, we felt confident that subjects would have adequate va riability in their BP to detect differences (unpublished BP variability data, 2001). Inc lusion and Exclusion Cr iteria The spec ific incl usion cri teria we re as f ollows: • men or women 21 to 65 yea rs diagnosed with hy pertension or taking antihypertensive me dications, living in the North Florida area. • ability to come to the rese arch of fice a t least fo ur times. • ability to speak and under stand English. • able to verbally c ommunicate with intact memory • ability to read Eng lish at an eighth grade leve l or greater. Subjects who could respond to requests for participation were considered to have adequate communication skills and memory ability. Subjects were e xcluded from the

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56 study if their h istory demonstr ated sig nifica nt cardi ovascula r, rena l, or psy chiatric diseases. There was no exclusion of subjects based on g ender or race. Setting The setting for this study w as a county located in Northern Florida. I nitially, the subjects were screened in the labora tory or f ield setting. The pretraining, training, a nd posttraining sessions occurred in the subjects’ natura l environment during day time hours while the subjects were awake. Researc h Varia bles and I nstrumen ts Demographic Data Sheet The demographic data sheet includ ed information regarding a ge, gender, ra ce, marital status, how long with diagnosis of hy pertension, height, weight, body mass index (BMI), and e ducation. Health History F orm The health history for m included yes/no ty pe questions regarding the pre sence or absence of health conditions including high B P, diabetes, heart and cerebral disease psy chiatric disorder s, and othe r chroni c disea ses. Addi tionally question s rega rding pa st or prese nt smoking alcohol use, hig h choles terol, e xercise le vel, medi cations, and fami ly cardiovascular health history were included. Ambulatory BP Monitor Natural istic ambu latory monitorin g of BP i n human sub jects wa s prefe rred in th is study because it enhances the generalizability of the findings to outside of the laboratory setting and it does not interfere with most of the subjects’ usual daily activities. The SpaceL abs ABPM (Model 90 207, Spac eLa bs, I nc., Redm ond, WA), a n automat ic noninvasive oscillometric recorder, was used to collec t SBP data. This monitor measures

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57 BP by detec tion of oscillations transmitted from the brachial artery to the cuff. The monitor was equipped with four different size adult cuffs. A Space Labs (Model 9029, Redmond, WA) Data Interfac e Unit was used for data retrieval a nd report generation. The ABPM can be programmed to display the BP readings on its’ L CD screen immediately after measurement (i.e., unblinded) or not to display the BP readings (i.e., blinded). This feature worked well for this study as different time periods required “blinding ” or “unb linding” of the L CD scre en. The r eliability of the Spa ceL abs ABPM device h as been s tudied exte nsively over the last few ye ars. Corr elation c oeffic ients between two sets of readings have r anged between 0.72 and 0.93 f or SBP, indicating that the relia bility is acce ptable ( Pickerin g et al ., 1994). Pickerin g et al. sugge st that at l east five or six readings would give an adequa te representation of the averag e pressure in a particular setting such as work or home. I n addition, a sampling frequency of one reading every 30 to 60 mi nutes has be en suggested to adeq uately describe average SBP levels in different settings. This instrument has a high leve l of accuracy and clinical performance and meets Association for the Advancement of Medical I nstrumentation guidelines and the guidelines of the Br itish Hypertension Society (O'Brien, Atkins, & Staessen, 1995). Artifactual readings we re eliminated using the Casadei procedur e, a standard editing criteria (Winnicki, Canali, Mormino, & Palatini, 1997). Similar to other editing criteri a, the Ca sadei pr ocedure eliminat es measu rements t hat fall o utside 50 t o 240 mmHg for SBP, 40 to 140 mmHg for DBP, 40 to125 beats pe r minute for heart rate, and 20 to 100 mmHg for pulse pressure. Rigorous calibration of the monitor was made prior to AB P monitoring. A calibration procedure comprised of three calibration readings taken simultaneously with a

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58 mercury column sphygmomanomete r and the ABP monitor, by means of a “T-connector” between the two instruments. Readings for both SBP and DB P agreed within 5 mmHg of one anoth er on all three a ttempts. For the purpose of this study the ABPM was initialized to measure BP every 30 minutes. Actual ambulatory B P measurements were recorde d as numerical continuous response variables. After measureme nt of ambulatory B P, BP data were downloaded using SpaceLabs Da ta Management Software (Re dmond, WA) and the data. Actual BP Actual BP was a continuous variable that was mea sured using a SpaceL abs Ambulatory BP Monitor (Model 90207, Spa ceLabs I nc., Redmond, WA). Estimated Systolic BP Estimated SBP was a continuous numerical variable that was estimated by the participant in mmHg and was based on the g uideline provided to the participant. Participants were also invited to circle the rang e of SBP that they thoug ht their SBP was in at the time of cuff inflation and BP measurement. This was done to improve the conceptualization of the participant to estimating his/her own SBP. I f range information was the only method of e stimating for the subject, the averag e of the range was computed and entered as the subjects’ estimation of SBP. Absolute Difference The absolute difference (AD) is de fined as the absolute value of the mean difference. The absolute differ ence was calculated for mean actual SBP day 1, mean estimated SBP day 1, mea n actual SBP day 4, and mean estimated SBP day 4.

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59 Mean Improvement The mean improvement is defined as the absolute value of the mean difference of day 1 (mea n actual SBP minus mean estimated SBP) minus the absolute value of the mean difference of day 4 (mean difference of a ctual SBP minus estimated SBP). Preand Pos ttraining S BP Estimat ion Form The preand posttraining SBP Estimation Form provides subjects with a guideline for SBP estimation that is based on the classification defined by the Joint National C ommittee on Preventi on, Detectio n, Evaluati on, and Treatm ent of High BP (JNC VI, 1997). This tool categorizes SBP base d on the JNC VI (1997) classification and prov ides cat egoric al descr iptions of e ach ran ge of SB P categ ory This ser ves to hel p subjects conceptualize their SBP, so that they can estimate their SBP level. Subjects are instructed to write an estimate of what they think their SBP level is at the start of cuff inflation. Subjects were instructed that they may circle the range of where they think their SBP falls, if this was more understandable for the subjec t. SBP Estima tion Trai ning Fo rm and Sel f-Awa reness Ch ecklist The training form is a form that is used during da ys 2 and 3. One f orm was used for eac h BP meas urement /estimatio n. The f orm consi sts of an a rea for the subje ct to write the time of BP measurement, estimated SBP level (subjec t estimates), and actual SBP level (from the monitor). The SelfAware ness Chec klist is a y es/no che cklist. I t is made up of 38 mood, symptoms, and situation items. This checklist has bee n adapted from research on phy sical symptoms and fac tors relating to BP (Barr et a l., 1988; Brondolo et al., 1999; Gellman et al., 1990).

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60 Demographic Variables Demogr aphic ch aracte ristics of subject s were e xamined by nine indic ators: gender, race, educ ation, marital status, age, height, weig ht, body mass index, and how long with diagnosis of hy pertension. Gender Gender was a categ orical variable coded as male or f emale. Race Race was a categoric al variable coded as White, Black, Hispanic, A sian, and other. Education Education was categorized into seven g roups according to the number of year s of formal education which the participants completed: less than 7 y ears, junior high sch ool (gr ades 7-9 ), some hi gh scho ol (gr ades 1011), hig h school g raduate some college or technical school, colleg e graduate, and g raduate school (master’s degr ee or beyond). F or data analy sis purposes, education was further compressed into two variables: H.S./technical school and college educated. Marital status Marital status was coded into one of four categ ories reflecting the status of married, widowed, divorced/separa ted, or never married. Age Age was recorded a s actual y ears and was coded into five categ ories reflec ting y ears of age: 21 -30, 31-4 0, 41-50 51-60, 6 1-65. Fo r data a naly sis purpos es, age wa s furthe r compre ssed into tw o categ ories: $ 48 years of age and < 48 y ears of age. Weight Weight w as a cont inuous nu merical variabl e that wa s recor ded in kilograms (kg). Height Heigh t was a co ntinuous n umerica l variab le that wa s recor ded in centimeters (cm). Bod y Mas s Ind ex (BM I) BMI was ca lculated as the ra tio of the w eight in kg to the square of the height in meters.

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61 Length of time since diagnosis of hy pertension Length of time since diag nosis of hypertension wa s categorized as follows: less than 5 y ears, 5-10 y ears, 11-20 y ears, 21 years or more. Health Status Variables Four indicators were utilized to identify the health status, family ca rdiovascular health history, and the use of prescribed and nonprescribed medic ines. These variables included (a) existence of health problems, (b) number a nd type(s) of me dications used daily (c) fa mily cardiov ascular health hi story and (d) lifesty le facto rs. Belo w is a descrip tion of the se varia bles. Health pr oblems The par ticipant was aske d to identif y hi s or her h ealth pr oblems from a list of different illnesses. The answer wa s coded zero when the problem did not exist and one if the problem existed. Use and type of medications The use of all ty pes of me dication s was a categorical variable that wa s coded zero if there were no medica tions used and one if the participant used medications on a daily basis. If the answe r was ye s, the participant was asked to n ame all pr escribe d and nonp rescr ibed medi cations th at are u sed daily For da ta analysis purposes, the medic ation variable was further descr ibed to account for differe nces amo ng ty pes of me dication s and an tihy pertens ive medic ations. A v ariable coded as “htntype ” was created and was c oded as 0 if they w ere taking no hy pertensive medications, 1 if they we re using ace inhibitors, 2 if they were using calcium channel blockers, 3 if they w ere using beta blockers, 4 if they were using diuretics, 5 if they were using other antihy pertensives, and 6 if they were using 2 or more antihy pertensive medicati ons.

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62 Family ca rdiovascular health history Each participant was asked to identify illnesses that his or her blood relative s have h ad or cur rently have. F amily cardiovascular health history was coded into five categor ical variables including heart attack, high BP, stroke, d iabetes and hig h choles terol. Th e answe r was co ded zero i f there was no family history of the disease The variable was coded 1 if there wa s a blood relative with one of the identified illnesses, 2 if there wer e 2 identified illnesses, 3 if there were 3 illnesses chosen, 4 if there were 4 chosen, and 5 if there were 5 illnesses c hosen. Life sty le facto rs. Lifesty le factors were considere d questions relating to alcohol use, caffeine use, exercise level, and c holesterol elevation. The responses were c oded zero if the responde nts chose no and one if the re spondents chose y es. Table 3-2. Instruments used and variable s measured during the study periods Instrument Variables ABP Monitor Actual SBP Pre-/Posttraining Form Estimated SBP Training Form/Sel f-Awar eness Checklist Estimated SBP Actual SBP Biosituational factors Demographic Data Sheet Gender Race Education Marital status Height Weight BMI Time with hypertension Veteran status Age Date of B irth Health History F orm Personal history of card iovascul ar, ren al, liver, thy roid dise ases, dia betes me llitus, caffeine, alcohol and tobacco use, e xercise, me di ca ti on us ag e, an d f am il y hi st or y.

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63 Classifi cation of Adu lt BP The criteria for classify ing BP as defined by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hig h BP (JNC VI, 1997) was used to assist su bjects to e stimate th eir actu al BP. Ta ble 3-3 sh ows the c lassific ation for adult BP as defined by the JNC VI (1997). Table 3-3. Adult BP classification Category Systoli c BP (m mHg) Diast olic B P (mm Hg) Optimal Less than 120 and Less than 80 Normal Less than 130 and Less than 85 High-Normal 130-139 or 85-89 Hypertension Stage 1 140-159 or 90-99 Stage 2 160-179 or 100-109 Stage 3 180 or greater or Greater than 110 Study Protocol and Procedur es This research consisted of three pha ses: (a) initial interview and pretraining measurement and estimation of BP (one day period), (b) ABPM and biosituational selfawareness trai ning (2-day period) and ( c) posttrain ing measuremen t and estim ation of BP (1-day pe riod). Subject Recruitment After the appropriate institutional review and appr oval, subjects were recruited from northern Florida. The investigator r ecruited participants using fliers and advertisements that were posted near the U niversity of Florida the Veterans Administration clinics, hospitals, and various public areas in the north Florida area Recruitment fliers were also sent to female ve terans with hyper tension in the northern Florida area. Attempts to include diverse par ticipants (i.e., gender, age and race) were

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64 made. Those subjects who met the inclusion criteria and who did not meet the e xclusion cr it er ia we re as ke d t o p ar ti ci pa te in th e s tu dy. Initial Screening Proce dures The initial screening occurred in e ither the laboratory or field setting. The procedure for measuring B P was in accordance with JNC VI recommendations, using the ABPM. To assure that the ABPM reading s are valid, calibration of the equipment was performed. The investigator calibra ted the ABPM using simultaneous determinations of BP by auscultation and a mercury sphygm omanometer (using T connector) and agreement of at least 3 sequential re adings to within 5 mmHg sy stolic and diastolic was found (NHBPEP-ABPM, 1992). The BP me asureme nt bega n after approxima tely 3 to 5 minute s of quiet rest, sitting in a chair. The subject was seated in a c hair with his/her back supported and nondominant arm bared and supported at the hear t level. The appropriate cuff size was determined to ensure accurate mea surement. The bladder within the cuff encir cled approximately 80 % of the subject’s a rm in accordance with JNC VI recommendations (JNC VI, 1997). The investigator provide d the subject with an initialized, programmed and fitte d ambulat ory BP monitor The inv estiga tor perf ormed two BP measu rements approximately two minutes apart, in acc ordance with recommendations of the JNC VI (1997, p. 12). If these two mea sures were more than 5 mmHg a part, a third measure was taken The av erage of the me asurem ents w ere pro vided to th e pati ent as their “average BP.” Ambulatory BP Monitoring Protocol The subject was instructed to refrain from e xcessive physical exertion and water activities while wearing the BP monitor. The subject wa s instructed to keep a regular

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65 sleep an d wake pa ttern an d to avoid a ny u nusual phy sical exer tion or exc essive str ess during the study pe riod. The subject was instructed that he/she could remove the monitor for short time periods if these activities were unavoidable. T hen, the subject was given the opportunity to use and bec ome familiar with the ABPM. Ambulatory BP wa s measured on an ordinary work, home, or school day for each subject. To ensur e that the subjects were e xperienc ing “usu al” sy mptoms or si tuations, subjects were asked prior to beginning each study day how they were feeling on that day and if they we re feeling “well” or “usua l.” If the subject wa s not feeling as he/or she normally fee ls (e.g., has a cold/flu or other anomaly ), the session was postponed until the following day or a more “usual” day To ensur e subjec t safety subject s were instructe d to sit, re st, and ca ll their primary hea lth care provider in the event that their BP wa s greater than 180 mmHg systolic or 110 mmHg diastolic over two consecutive periods. Because of the nature of the ABPM device, subjects were instructed tha t they could push the “start” button on the mo ni to r an d m eas ure th eir BP i n m ore fre que nt in ter val s t han wer e pr ogr amm ed. In addition, subjects were instructed to call their health car e provider or seek emerge ncy care if they experienced any other serious discomforts other than the minimal discomforts associated with the use of the ambulatory BP monitor. Subjects were instructed that symptoms such as chest pa in, shortness of breath, or numbness or tingling of face, legs, or arms should be re ported immediately to their he althcare provider. Subjects were fitted with an ABP monitor and familiarized with its use. The monitor was programmed to measure BP e very 30 minutes over a 6-hour period. Subjects w ere instr ucted tha t they could we ar the mo nitor dur ing thei r usual a wake hou rs, generally between the hours of 6 am and 10 pm. Each subjec t was fitted with a proper-

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66 sized BP cuff, fitted according to JNC VI recommendations (JNC VI, 1997). To ensure that the cuff was not too tight, the investigator inserte d a finger between the bladde r of the cuff and the su bjects’ a rm. Subjec ts were provided an ABPM to te bag o r hip stra p to assist in carrying the ABP monitor. The monitor emits a series of 5 beeps prior to measurement of BP and cuff inflation. The subject was instructed to listen for these sounds and to hang the ir arm freely at their side during cuff inflation. They were also instructed to keep the bladder of the cuff at or near the level of their he art, to avoid measurement errors. At cuff inflation, subjects were ins tructed to estimat e their BP. On da ys 2 and 3, sub jects we re also instructed to document their actual SBP as well as their moods, sy mptoms, and activities during t he BP mea suremen t. Da y 1 After the initial screening for inclusion/exclusion criteria, a convenient meeting date and time to start the study wa s arranged. I nformed consent was obtained and a copy of the informed consent and contact information for the investigator and dissertation chairperson was provided to each par ticipant. Subjects were informed that participation in this study will not change the wa y they are treated for high B P. The subject was instructed to continue doing exactly what his/her doctor has prescribed. Eac h participant was advised of his or her rights as a re search participant and the rig ht to decline without penalty. The investig ator arranged a time a nd place for the initial interview, either at the research office or the subjec t’s home. The investigator instructed the subject about the study procedu res and t hat data would be c ollected over a 4day period. T he parti cipants were notified that there was monetary compensation of $10.00 per day for each day that was completed.

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67 After informed consent was obtained, the subjec t was asked to answer questions related to demographics, health status, family history, and medication usag e. The entire interview took approximately 15-30 minutes per subject. After completion of the initial interview, data were entered into a da ta spreadsheet for analy sis. When the subject was comfortable with the ABPM operation and f unction, the subject s tarted D ay 1 data co llection p eriod a nd took the ABPM home work an d/or to their “n atural” environm ent. The particip ant was in structed to estimat e numeri cally their SBP using guidelines from the JNC VI (1 997). The LCD scree n on the ABPM was “blinded ” (i.e., no BP rea dings we re displ ay ed). The subject w as instruc ted to re turn to the clinic the following day with the ABPM, or arrangeme nts for a field visit were made. Days 2 and 3 On the second study da y, day 1 data were downloaded and edited using the SpaceLabs (Model 9029, Redmond, WA) Da ta Interface Unit. Data were entered into a data spreadsheet for analy sis. The ABPM was initialized and reprogrammed to display the BP readings on the L CD screen. The subject was provided informa tion on potential biosituati onal fac tors that m ay affec t BP. The subject w as give n the oppo rtunity to use and become familiar with the Training Fo rm/Self-Awareness Checklist. The subject was instructed to fill out the Self-Awareness Checklist at each B P reading. The subject was instructed that SBP, D BP, and HR are v isible in t he LCD screen after each BP measurement. Next, the subject was asked to look at and write down his or her actual SBP level as it appe ars on the LCD sc reen a fter ea ch read ing. Subj ects wer e instruc ted to estimate their SBP in a similar fashion as in day 1, when the cuff began to inflate. When the subject was confident with using the Self-Awar eness checklist and Training Form, he or she wa s instruct ed to we ar the AB PM for two c onsecuti ve day s in

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68 the “nor mal” env ironment a nd perfo rm the ins tructed tasks eve ry 30 minutes for six ho ur s e ac h d ay. Da y 4 On the fourth study day the subject and investigator met aga in. The data were downloaded onto a spreadsheet for analy sis. The ABPM was initialized and reprogrammed not to display the BP readings. Similar to day 1, the LCD screen wa s “blinded” to the subject (i.e., the BP reading were not be visible to the subject). The subject w as instruc ted to think about the biositua tional fa ctors tha t occurr ed during their SBP measu rements a nd when SB P was hig h. Subjec ts were g iven an op portunity to assess the biosituational self-awareness fac tors that were related to high SBPs (acc ording to individual responses). Subjects w ere instr ucted to w ear the ABPM monit or for 6 h ours and e stimate their SBP, making decisi ons based on their biosi tuational self-awareness factors and BP readings, during the previous 2 day s. At the conclusion of the study, subje cts were instructed to return the ambulatory BP monitor and all f orms to the investig ator. Sub jects we re thank ed for th eir participation and were given a printed a nalysis of the 4-da y ABPM rea dings. Each subject r eceive d $10.00 c ompensat ion for e ach day they complete d. The sub jects received a total of $40.00 monetary compensation for participation in this study. Study procedures are outlined in Table 3-4. Methods of Statistical Analyses Data were analy zed using SPSS (SPSS, Inc., Chicago, I llinois). Descriptive statistics were computed to obtain the summary measures for the data addressing the research hypotheses. E stimated S BP data was obt ained from t he pre-/post training SBP

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69 Estimation Form. Actual SBP measurement data was obtained fr om the data recorded using the ABP monitor and the report gen erated by the SpaceLabs (Space Labs, I nc., Redmond, WA) Data Interfac e Software. These data wer e entered into data files for analysis using Micr osoft Excel (Microsoft Inc.) softwa re and SPSS (SPSS, Inc., Chicago, Illinois) statistical software. Descriptive statistics were computed to identify the demographic characte ristics of the participants, number and ty pes of medications used, health pr oblems, a nd family health hi story Study variabl es (estim ated and actual SB P, absolute differe nce (AD ) of the me an scor es of day 1 and 4, a nd mean im proveme nt) were summarized and graphed ac ross time. For data analy sis purposes, day 2 and 3 we re combined and a total mean score for actua l SBP, estimated SBP, and absolute difference were calculated for the two day s. Analysis conc erning the relationships between actual and estimated SBP were performed using paired-samples t-tests. For Hy pothesis 1 and 3, paired-samples t-tests were used to compare the mean improvement between day 1 and day 4 within g roups. F or Hy potheses 2 and 4 th rough 7 indepen dent samp les t-tes ts were used to compare the means betwe en groups of subjects. See Table 3-1 f or a de sc ri pt io n o f t he de si gn a na lys is gr ou pi ng s, an d d at a m ea su re d i n t hi s s tu dy.

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70 Table 3-4. Procedures for SBP estimation study Phase 1: Initial I nterview and Pretraining (Day 1) In labor atory/Fi eld S etti ng: Screen f or In clusion/E xclusion c riteria Info rmed Conse nt Proces s Calib rate & ini tiali ze AB PM (B P rea ding s not s hown ) and dete rmine cuff size Obtain demographic, health status, health and fa mily health history and medicati on usag e data Provide b asic inform ation abou t SBP Obtain “average” ba seline BP and provide information to subject Intr oduction t o Pre-/Pos ttraining Estimatio n Form an d ABPM Allow subj ect to pr actice using SB P estimatio n form an d ABPM In na tural set ting: Subject estimates SBP (LCD blinded) for 6 hours a t start of each cuff inflation Phase 2: Training (Day s 2 & 3) In la borator y: Initialize ABPM (BP reading s shown) Provide information on SBP Estimation and BSMA factors Demonstr ate ABPM and Tra ining F orm/SelfAwaren ess Chec klist Allow subj ect to pr actice using A BPM, BP e stimation, and SelfAwaren ess Checklist In natur al set ting: Subject estimates SBP for 6 hours at start of cuff inflation Complete Training Form (SBP estimation, Self-Aware ness Checklist, & actual SBP) Phase 3: Posttraining (Day 4) In l ab or at or y: Initialize ABPM (BP reading s not shown) Instruct patient s to thin k about bios ituation al self-awarenes s factors & SBP feedback whil e estimati ng their SBP In natur al set ting: Estimate SBP (LCD blinded) for 6 hours a t start of cuff inflation

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71 CHAPTER 4 RESULTS The prima ry purpose o f this study was to de termine i f hy pertens ive pers ons could learn to estimate their SBP using a B P feedb ack and biosituati onal self -aware ness training int ervention. This was det ermined by comparing th e accuracy of the SBP estimatio n before and afte r trainin g. The seconda ry purpose o f this res earch w as to compare the differences in the mea n improvement of actual to estimated SBP between different groups of hy pertensives within the sample. These groups include c ollegeeducated (CE) hy pertensives compared to non-CE (NCE) hy pertensives, hype rtensives wit h a b ody m ass in dex (BM I) < 3 0 co mpa red to hype rte nsi ves wit h a B MI 30, male hypertens ives c ompar ed to f emale hypertens ives, hypertens ives l ess th an 48 years of age compare d to hy pertens ives $ 48 years of age, and hy pertensive medication (HM) users compared to hype rtensive medication (HM) nonusers. This chapter will first present descriptive statistics, including means, standa rd deviatio ns, and fr equenc y di stribution s for ea ch varia ble. The hyp otheses p osed in Chapter 1 will be addressed using paired sa mples t-tests and independent samples t-tests. For all r esults, da ta will be expresse d as mea ns standa rd devia tions and/ or perc entage s. Descri ptive Resu lts Sample Characteristics Over 60 potential subjects were scree ned for inclusion in this study. However only 42 subjects met the final inclusion cr iteria. Of these 42 subjects, 3 subjects were

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72 excluded from the analy sis for different reasons. One male subjec t was excluded after completion of day 1 bec ause his BP on day 1 was low. This subject had a mean SBP on day one of 101 mmHg and a minimum BP of 74/52. The subject reported sy mptoms of “not feeling well” and was being treated for chronic hy pothyroidism. I t was recommended that the subject seek care from his healthcare provider and withdra w from the study. A female s ubject was ex cluded from t he study after day 1 because her BP levels were ex cessively high. Her mean SBP level was 192 mmHg and h er maximu m BP was 201/116. She was advised to obtain immediate medical care. She c ontacted her physician, obtained medica l treatment, and was released from the study A third subject withdrew from the study a fter day 1 because of difficulties that she had in perfor ming the protocol activities during her normal work/home day A total of 39 subjects completed the study protocol. Of the total, 15 subjects were male and 24 subjects were female. The m ale group ranged f rom 26 to 65 years with a mean age of 45. 1 years. Th e femal e group r anged fr om 21 to 65 years, wit h a mean age of 50.4 year s. Subject demographics expressed in numbers and perc entages were g ender, race, age, ma rital sta tus, famil y hi story of hy perten sion, vete ran statu s, time with diagno sis, education level, hy pertension medication ty pe, overall medication ty pe, and habits of cigarette smoking, alcohol use, ca ffeine use, and exercise. Table 4-1 shows the subject demogr aphics f or the tota l hy pertens ive samp le (N = 39 ), NCE sub jects (N = 15), an d CE subjects (N = 24). Table 4-2 compares the lifestyle variable s for the total hyper tensive sample, NCE subjects, and CE subjects. Table 4-3 compares the he alth status data of the total sample of hyperte nsives, NCE subjects, and CE subjects.

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73 Table 4-1. Comparison of demographic data for the total sample, college-educated subjects and nonc ollege -educa ted subje cts Total sam ple (N = 39) Noncollegeeducate d subject s (N = 24) College-educated subjects (N = 15) N (%) N (%) N (%) Gender Male Female 15 (38.5) 24 (61.5) 9 (37.5) 15 (62.5) 6 (40) 9 (60) Race Caucasian African American 32 (82.1) 7 (17.9) 18 (75.0) 6 (25.0) 14 (93.3) 1 (6.7) Age 30 and under 31-40 year s 41-50 year s 51-60 year s 61-65 year s 4 (10.3) 5 (12.8) 12 (30.8) 13 (33.3) 5 (12.8) 1 (4.2) 2 (8.3) 6 (25.0) 12 (50.0) 3 (12.5) 3 (20.5) 3 (20.5) 5 (33.3) 2 (13.3) 2 (13.3) Martial Status Married Never married Widowed Divorced 27 (69.2) 3 (7.7) 2 (5.1) 7 (17.9) 16 (66.7) 2 (8.3) 2 (8.3) 4 (16.7) 11 (73.3) 1 (6.7) 0 (0.0) 3 (20.0) Education Level HS grad uate Some college/tech. College gradu ate Graduate school 8 (20.5) 16 (41.0) 6 (15.4) 9 (23.1) 8 (33.3) 16 (66.7) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 6 (40.0) 9 (60.0) VA/Vete ran Aff iliate No Yes 22 (56.4) 17 (43.6) 18 (75.0) 6 (25.0) 4 (26.7) 11 (73.3) Table 4-2. Compariso n of lifes tyle data fo r the tota l sample, c ollege -educa ted subje cts, and nonc ollege -educa ted hy perten sive subje cts Total sam ple (N = 39) Noncollegeeducate d subject s (N = 24) College-educated subjects (N = 15) N (%) N (%) N (%) Current T obacco Use No Yes 30 (76.9) 9 (23.1) 18 (75.0) 6 (25.0) 12 (80.0) 3 (20.0) Regula r Alcoho l Use No Yes 18 (46.2) 21 (53.8) 13 (54.2) 11 (45.8) 5 (33.3) 10 (66.7) Regula r Caffe ine Use No Yes 5 (12.8) 34 (87.2) 5 (20.8) 19 (79.2) 0 (0.0) 15 (100.0) Regula r Exercis e No Yes 15 (38.5) 24 (61.5) 10 (41.7) 14 (58.3) 5 (33.3) 10 (66.7)

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74 Table 4-3. Comparison of health status data for the total sample, college -educated hyp ertensiv e subjec ts, and no ncolleg e-educ ated hy pertens ive subje cts. Total sa mple (N = 39) Noncollegeeducate d subject s (N = 24) College-educated subjects (N = 15) N (%) N (%) N (%) Time with diagnosis of hype rtension Less than 5 y ears 5-10 year s 11-20 year s 21 or more ye ars 27 (69.2) 6 (15.4) 4 (10.3) 2 (5.1) 14 (58.4) 6 (25.0) 2 (8.3) 2 (8.3) 13 (86.7) 0 (00.0) 2 (13.3) 0 (0.0) Family history of card iovascul ar disea se No family history 1 FH item selected 2 FH item selected 3 FH item selected 4 FH item selected 5 FH item selected 2 (5.1) 4 (10.3) 9 (23.1) 6 (15.4) 10 (25.6) 8 (20.5) 0 (0.0) 2 (8.4) 6 (25.0) 3 (12.5) 5 (20.8) 8 (33.3)* 2 (13.3) 2 (13.3) 3 (20.0) 3 (20.0) 5 (33.4) 0 (0.0)* Hypertension medic ation type Not taking HTN meds Ace inhib itor only Calcium c hannel bl ocker on ly Beta blo cker onl y Diuretic Only Other HT N med only 2 or more HTN meds 16 (41.0) 8 (20.5) 3 (7.7) 2 (5.1) 2 (5.1) 1 (2.6) 7 (18.0) 9 (37.5) 4 (16.7) 3 (12.5) 0 (0.0) 2 (8.3) 1 (4.2) 5 (20.8) 7 (46.7) 4 (26.7) 0 (0.0) 2 (13.3) 0 (0.0) 0 (0.0) 2 (13.3) Overall medication type Not taking medications Taking HTN meds o nly Taking other ty pe of med s only Taking other med and HTN med 6 (15.4) 10 (25.6) 10 (25.6) 13 (33.4) 3 (12.5) 4 (16.7) 6 (25.0) 11 (45.8)* 3 (20.0) 6 (40.0) 4 (26.7) 2 (13.3)* indicates p # 0.05 by Mann-Whitn ey -U Nonp arametr ic Tests. Clinical Characteristics The cli ni cal cha rac ter is ti cs o f th e su bj ect s, i ncl udi ng a ge, wei ght he igh t, BMI, actual and estimated SBP day 1, actual and estimated SBP day 2 and 3, actual and estimated SBP day 4, mea n absolute differences of actua l SBP (ASBP) minus estimated SBP (ESBP) for each day and number of observations are expressed using means and standard deviations and are presented in Ta ble 4-4. The mean scores for eac h study day and acr oss all stud y da ys a re summar ized in Ta ble 4-4. T he mean A SBP measu rements

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75 were similar among the total sample on day s 1 and the average of day s 2 and 3; 137.0 11.0 mmHg and 136.1 15.3 mmHg, respectively On day 4, the mea n ASBP was slightly lower a t 136.1 12.1 mmHg, but this reduction was not statistically sig nificant. Among the 39 s ubjects, t here were 485 BP mea surements/ estimati ons on day 1, 880 BP measurements/estimations on day 2 a nd 3, and 482 BP measurements/estimations on day 4. In total, there were 1847 BP measurements/estimations among the 39 subjects for the total 4-day study period. Table 4-4. Clinical characteristics for the total sample (N = 39) Total Sample (N = 39) Initial screening Da y 1 Day 2 & 3 Da y 4 Ag e (yrs.) 48.4 11 .5 W eight (lbs.) 194 .1 4 6.3 He ight (in.) 66.7 4.6 BM I (kg/m 2 ) 30.5 5.4 Actual SBP (mmH g) 137 .0 1 1.0 137.1 9. 27 136 .1 1 2.1 Mean A ctual SBP Ran ge (mmH g) 51 36 52 Min A SBP (mmH g) 94 91 99 Max ASB P (mmH g) 176 192 174 Estimated SBP (mm Hg) 137 .3 8 .6 136.0 5. 49 136 .1 1 1.8 Absolute differ ence ASB P-ESB P (mmH g) 10.1 3.5 7.5 5. 70 9.3 3.2 Number of ASBP-ESBP observ ati ons 12.4 2.3 20.9 6.9 12.3 1.7 Analytic Results for H ypotheses Procedure for Calculating Mean Score s As descr ibed pre viously the study protocol involved 4 day s of BP me asureme nt, at a frequency of every 30 minutes for 6-hours each day Therefore, theoretically each subject should have 12 observations or BP measurements/estimations per day However, on Day 1, the number of BP observations for each subject ra nged from 9 to 20 observations, with a mean number of observations at 12.4. L ikewise, on day 4 the number of BP observations for each subjec t ranged from 9 to 15 observations with a mean of 1 2.3 obser vations. T his varia tion occ urred f or a numbe r of rea sons. Fir st, some

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76 subjects correctly had their BP taken 12 times but the BP measurement was de leted due to an error. The error may have been caused by improper inflation/position of the cuff, too much activity of the ar m or body during cuff inflation, and/or the BP reading wa s higher than the p revious B P reading and the c uff did no t inflate to an ade quate le vel to obtain the reading. Secondly a few subjects did not follow instructions completely and performed either too few (9 to 11) rea dings or too many (13 to 20) readings. The majority of subjec ts perfo rmed the tasks as directe d and per formed 1 2 readin gs. Dat a were inc luded if th ere we re at lea st 9 obser vations pe r day All 39 sub jects ha d at leas t 9 observations per day To assure that the mean score ref lected the variation in number of observa tions per day each in dividual s ubject’ s scores were a naly zed separ ately to compute a mean actual SBP, mean estimated SBP, and a mean absolute difference between actual and estimated SBP for eac h subject. Absolute difference. The abso lute diff erence (AD) is d efined a s the abso lute value of the mean difference. Without using a bsolute difference, overestimates and underestimates would average to a smalle r mean difference. The absolute diff erence has been calculated for day 1 (mean actual SBP minus estimated SBP day 1), day 2 and 3 (mean actual SBP minus estimated SBP day 2 and 3 combined), and day 4 (mean actual SBP minus estimated SBP day 4). Mean impr ovement. The mean improvement is defined as the absolute value of the mean difference of day 1 (mean actual SBP minus mean estimated SBP) minus the absolute value of the mean difference of day 4 (mean difference of ac tual SBP minus estimated SBP). The mea n improvem ent represents a measure of im provement i n SBP estimation between day 1 and day 4.

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77 The Paired Sample t-Test The paired sample t-test was used to compare the means of two scores from related samples. The assumptions of a paired t-test are that the variables are at interval or ratio levels and that they should be normally distributed. Figure 4-1 depicts the improvement scores of the entire sample of adult hypertensives. It illustrates a relatively normal distribution of improvement scores. Because of the robustness of a t-test, it is appropriate to use a paired t-test for these data. The Independent Samples t-Test The independent samples t-test compares the means of two independent groups. The assumptions of this test are that the two groups are independent of each other, the dependent variable must be measured on an interval or ratio level, and the scores should be normally distributed. All assumptions have been met for this test (refer to Figure 4-1) for distribution of mean improvement scores. Figure 4-1. Distribution of mean improvement scores for total sample (N = 39). Mean and standard deviation of the improvement in SBP estimation for the entire sample of hypertensive persons is provided.

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78 The mean actual SBP and estimated SBP across a ll study day s was 136.5 and 136.1 mmHg, respectively The mean difference a cross all study day s was + 0.43 mmHg. Th is finding sugge sts that sub jects we re extrem ely accura te in estim ating th eir SBP; howev er, the mean di fference does not take into acco unt the vari ability of SBP measurement/estimations and the overand undere stimators of SBP. The absolute value of the difference between e stimated and actual SBP for each subject wa s calculated and averaged and was found to be 8.6 mmHg. Therefore, subjects we re actually estimating on average within 8.6 mmHg of their a ctual SBP level across all study days. The AD was calculated and used in this study to take into consideration that there would be overand unde restimat ions of SB P and to g ain the t rue pict ure of SB P eliminati on. This me th od ha s b ee n u se d b y Lub or sk y et al ( 19 76 ) i n a si mi la r B P e st im at io n s tu dy. Hypothese s Hypothesis 1. Adult hypertensives diffe r significantly in their mean AD after the ambulatory B P awareness training intervention, compar ed with before the training intervention. For hypothesis 1, the mea n absolute difference of day 1 was compared to the mean abs olute diff erence of day 4, using a paire d-sample s t-test. T he mean a bsolute difference on day 1 (pretraining) was 10.1 3.5 mmHg a nd the mean absolute difference on day 4 (posttra ining) w as 9.29 3 .2 mmHg The hy pertens ive subje cts improv ed their mean scores after the training, how ever the improvement was not statistically significant (t = 1.094, df = 38, p = 0.281). Of the 39 subjects, 18 subjects showed no improve ment and 21 subjects (54%) showed improvement in estimating their SBP af ter the training. See Figure 4-1 for a g raphical display of the AD of day 1 minus the AD of day 4 (me an improvement) of the total hype rtensive sample. As Figure 4-1 shows, the me an improvement was 0.8 4.4 mmHg for the total sample of hy pertensive subjects (N = 39).

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79 Hypothesis 2. College-educated hy pertensives differ significantly from noncollegeeducated hy pertensives in their mean improvement of SBP estimation. For hy pothesis 2 CE hy pertens ives we re compa red to NCE hyp ertensiv es to assess di ffere nces in th eir mean improvem ent scor es for da y 1 a nd day 4. The CE subgroup was composed of 15 subjects (6 males, 9 fe males), mean age 43.2 13.7, mean BMI = 29.02, and mea n improvement 2.0 4.1 mmHg. The NCE subgroup was compo sed of 24 sub jects (9 mal es, 15 female s), me an imp rovem ent 0. 04 4. 5 mmH g, mean age 51.6 y ears, mean BMI 31.4. The CE and NCE groups had similar marital status an d freque ncies of reporte d tobacc o, caff eine, an d alcohol use. Compa red to CE subjects, NCE subjects were older (p = 0.05), more frequently ta king medications for hypertension (p = 0.05), and had more family cardiovascular disease history (p = 0.05). In addition, trends in NCE subjects included a long er personal history of hyperte nsion, less alco hol use, a nd had a g reater Africa n Americ an raci al perc entage ; howeve r, these were not statistically sig nificant compared with CE subjects. The mean actua l SBP for the CE group was significantly lower compared to the NCE group on da y 1; 132.8 mmHg and 139.6 mmHg respectively (p = 0.05). Similarly, the me an SBP on day 4 wa s lower for the CE group, however not significa ntly (p = 0.108). Re fer to Tables 4-1, 4-2, 4-3, and 4-5 f or demog raphic, health sta tus, life sty le facto rs, and c linical da ta for the se groups. To test hypothesis 2, an independ ent samples t-test was used. The difference between the two groups was not statistically significant (t = -1.333, df = 37, p = 0.19). The mean improvement scores of NCE hy pertensives (mean improvement 0.04 4.5 mmHg) were not significantly different than the mean improvement of CE hy pertensives (mean imp rovemen t = 2.0 4.1 mmHg). Becau se the an aly sis perfo rmed in hy pothesis 2

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80 is comparing the two independent groups improve ment using an independent samples t-test, it is unclear if the college-educa ted group alone improved significa ntly between day 1 and d ay 4. There fore, a paired -sampl es t-t est wa s perfo rmed t o asse ss th e change in mean AD from day 1 to day 4 among the CE subjects. Hypothesis 3. College-educated hy pertensives decrease their mea n AD post-training compa red to pretr ainin g. A paired samples t-test was calculated to compar e the pretraining mean AD to the posttraining mean AD among CE hy pertensives. The mean AD on day 1 was 9.74 3.4 mmHg an d the mea n AD on da y 4 w as 7.78 2.0 mmHg A signi ficant d ecrea se in mean AD from pretraining to posttraining was found using a one-tailed test (t = 1.86, df =14, p = 0 .04). Thi s supports the hy pothesis that CE hy pertens ives impro ve their accuracy significantly a fter training. Refer to Tables 41, 4-2, and 4-3 for a description of the de mograp hic, hea lth status, and life sty le facto rs data o f the CE su bjects. Re fer to Table 45 for a de scription of the cl inical c haract eristics of the g roup of CE hypertensives, e xpressed using means and standard deviations. An independent samples t-test was calculated to compar e the mean improvement scores o f female CE hy pertens ives comp ared to mean impr ovement s cores of male CE hypertensives. The mean improvement scores for female CE hy pertensives (N = 9) was 3.31 4.76 mmHg. The mean improvement for male CE hy pertensives was –0.093 1.17 mmHg. This difference between g roups approached, but did not reach statistical signific ance (p = 0.069) As shown in Fig ure 4-2, male CE hy pertens ives act ually worsene d their a bility to estimat e their SB P after th e trainin g, while the fema le CE hypertensives improve d at near statistically significant levels (p = 0.069).

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8 1 Table 4-5. Clinical characteristics of college-e ducated hype rtensives (N = 15). College -educa ted hy pertens ives (N = 15) Noncollege-educated hy pertensives (N = 24) Initial screening Da y 1 Da y 4 Initial screening Da y 1 Da y 4 Age (y rs.) *43.2 13.7 *51.6 8.8 Weight (lbs.) 191.0 47.9 196.0 46.2 Height (in.) 67.7 4.2 66.1 4.8 BMI (kg/m 2 ) 29.0 5.0 31.4 5.6 Actua l SBP (mmHg) *132.8 10.3 132.1 11.3 *139.6 10.8 138.5 12.1 Estimated SBP (mmHg) 135.9 7.8 132.7 10.6 138.1 9.2 138.2 12.2 Absolute difference ASBP-ESBP (mmHg) 9.7 3.4 7.8 2.0* 10.3 3.7 10.2 3.5 Number o f ASBPESBP Observations 12.8 2.9 13.1 1.6 12.2 1.7 11.8 1.6 Values are expressed as means standard devia tions. p # 0.05 ver sus prete st score s by paired t -test with in group s or inde pendent s amples ttests betw een gr oups.

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82 8.35 8.44 7.35 10.670 2 4 6 8 10 12 malefemaleMean Absolute Difference day 1 day 4Figure 4-2.Gender effects on estimation of SBP among college-educated hypertensives (N = 15). Hypothesis 4.Hypertensives with a BMI <30 differ significantly than hypertensives with a BMI 30 in their mean improvement. To test the hypothesis that hypertensives with a BMI < 30 differ significantly than hypertensives with a BMI 30 in their mean improvement, an independent samples t-test was used. The BMI < 30 group was composed of 17 subjects; 3 males and 14 females. The BMI 30 group was composed of 22 subjects; 12 males and 10 females. Compared to BMI < 30 group, subjects with BMI 30 had significantly more males (p = 0.02), asthma (p = 0.05) and showed trends toward more chronic pain history (p = 0.06) and less exercise (p = 0.09). The mean actual SBP for the BMI < 30 group (N = 17) was greater than the mean actual SBP of the BMI 30 group of subjects; however this difference was not statistically significant. The BMI < 30 groups mean actual SBP was 139.5 on day 1 and 138.2 on day 4. The BMI 30 group had a mean actual SBP of 135.1 mmHg on day 1 and 134.5 mmHg on day 4. An independent samples t-test was calculated to compare the mean improvement score of the BMI < 30 subgroup with the mean improvement score of the BMI 30

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83 10.65 9.64 9.7 8.96 3 4 5 6 7 8 9 10 11 12BMI less than 30BMI greater than 30Mean Absolute Difference Day 1 Day 4subgroup. The mean improvement score of the BMI < 30 subgroup was .9 3.9 mmHg and the mean improvement score for the BMI 30 subgroup was .7 4.9 mmHg. The mean improvement scores of the BMI < 30 group were not statistically different than the mean improvement scores of the BMI 30 group (t = -.158, df = 37, p = .875). Figure 4-3 shows the effects of BMI level on estimation of SBP as measured by absolute differences of actual and estimated SBP for days 1 and 4. As shown in Figure 4-3, both subgroups of BMI had decreases in their mean AD between day 1 and day 4; however, these trends were not statistically significant. Figure 4-3.BMI Effects on Estimation of SBP in Total Sample (N = 39). Hypothesis 5.Male hypertensives differ significantly in their mean improvement, compared with female hypertensives. To test the hypothesis that male hypertensives differ significantly in their mean improvement, compared with female hypertensives, an independent samples t-test was performed. There were 15 male subjects and 24 female subjects. Comparing both groups, male mean age was 45.1 years versus 50.4 years (p = 0.17) and mean BMI was

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84 32.3 ver sus 29.3 (p = 0.06). The gr oups diff ered sig nifican tly i n terms of medicati on use (p = 0.02) and medication ty pe (p = 0.01). Among females, 96% reported taking one medication on a daily ba sis compared with 67% males. Seventy percent of females reported taking antihy pertension medications, whereas only 40% of males reported taking hype rtension medications. Mean BMI for males was higher than female s (32.3 kg/m 2 versus 29.3 kg/ m 2 respectively ) (p = 0.07). Actual SBP levels for day s 1 and 4 we re no t s ig ni fi ca nt ly d if fe re nt be tw ee n m al es co mp ar ed to fe ma le s. Int er es ti ng ly, female subjects mean actual SBP decrea sed from 136.6 mmHg on day 1 to 134.8 mmHg on day 4. The mea n actual SBP was also lower for the fema les compared with the males. Additionally, the males’ mean a ctual SBP increased between day s 1 and 4, while the females’ mean actual SBP decrea sed. These trends in mean SBP were not found to be statistically significant. An independent t-test was calculated compar ing the mean improvement scores of male hyperte nsive subjects to female hy pertensive subjects. No significant differ ences were fo und (t = .752, df = 37, p = .45 7). The mean impr ovement o f the male hypertensives ( 0.1 4.4 mmHg) was not significantly different than the mean improvement of the female hy pertensives (1.2 4.5 mmHg). Figur e 4-4 shows the effec ts of ge nder on e stimation o f SBP amo ng the to tal sample of hy pertens ive subje cts (N = 39). Hypothesis 6. Hy pertens ives < 48 y ears of age dif fer sig nifican tly c ompared to hyp ertensiv es $ 48 years a nd older. To test the hyp othesis tha t hy perten sives < 48 ye ars of a ge diff er sign ificantl y compare d to hy pertens ives $ 48 years a nd older, an independent samples t-test was performed. The < 48 y ears of age gr oup was composed of 24 subjects (8 males and 16

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85 10.7 9.5 9 9.128 8.5 9 9.5 10 10.5 11Day 1Day 4Absolute Difference Male Femalefemales). The 48 years of age group was composed of 15 subjects (7 males and 8 females). Both groups were similar for all demographic variables except education level (p = 0.03). Sixty percent of younger subjects were college-educated compared with 25% for the older group. The mean actual SBP for the < 48 years of age group was 130.8 mmHg for day 1 and 131.3 mmHg for day 4. The mean actual SBP for the 48 years of age group was 140.9 mmHg for day 1 and 139.0 mmHg for day 4. The < 48 years of age group had significantly lower actual SBP than the 48 years of age group on days 1 and 4 (p = 0.004 and p = 0.05 respectively by independent samples t-test). Figure 4-4.Gender Effect on Estimation of SBP in Total Sample (N = 39). An independent samples t-test was calculated comparing the mean improvement of hypertensives less than 48 years of age to hypertensives aged 48 years and older. The mean improvement of hypertensives less than 48 years of age (0.9 2.9 mmHg) was not significantly different than the mean improvement of hypertensives 48 years of age and older (0.71 5.2 mmHg). No significant difference was found (t = .117, df = 37, p = .907). Refer to Figure 4-5 for graphical presentation of these results.

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86 8.7 10.9 7.9 10.20 3 6 9 12Age less than 48Age greater or equal 48Absolute Difference Day 1 Day 4Figure 4-5.Age and Estimation of SBP in Total Sample (N = 39). Hypothesis 7.Hypertensives using antihype rtension medication differ significantly in their mean improvement compared with hypertensives not taking medications. To test the hypothesis that hypertensive s using antihypertension medication differ significantly in their mean improvement compared with hypertensives not taking medications, an independent samples t-te st was performed. The HM nonuser and HM user subjects were similar in age, marital status, and education level. The HM nonuser subjects trended to be more overweight, had the diagnosis of hypertension longer, and had higher actual and estimated SBP compared with the HM users; however, these trends were not significant. The HM users mean SBP on days 1 and 4 were similar to the HM nonusers; with a mean actual SBP of 136.5 for HM users and 137.7 for HM nonusers for both days. Refer to Table 4-6 for a description of the HM users and nonusers. Values are expressed as means standard deviations, frequencies, and percentages. An independent samples t-test was calculated comparing the mean improvement of hypertensives using HM (N = 23) to hypert ensives not using medication (N = 16). A significant difference was found between groups (t = 2.038, df = 37, p = 0.05) for a two-

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87 tailed test (p # 0.05). Figure 4-6 compare s the mean improvement between both groups. The mean improveme nt of the H M nonuse r group (2.4 5.2 mmHg) w as signi ficantly better than the group using HM (-.4 3.4 mmHg). Table 4-6. Description of antihype rtension medication user and nonusers HM user (N = 23) HM nonuser (N = 16) Age 49.2 10.7 47.2 12.8 Gender 6 males, 17 females 9 males, 7 females Education level Noncollege educated College-educated 15 (65.2%) 8 (34.8%) 9 (56.2%) 7 (43.8%) Race Caucasian African American 18 (78.3%) 5 (21.7%) 14 (87.5%) 2 (12.5%) Time with d iagnosi s Less than 5 y ears 5-10 year s 11-20 year s 21 or more ye ars 14 (60.9%) 3 (13.0%) 4 (17.4%) 2 (8.7%) 13 (81.3%) 3 (18.8%) 0 (0.0%) 0 (0.0%) BMI 29.6 5.5 31.8 5.3 ASBP day 1, mmHg 136.4 12.0 137.9 9.6 ESBP day 1, mmHg 135.6 9.5 139.7 6.9 ASBP day 4, mmHg 135.1 13.5 137.5 10.0 ESBP day 4, mmHg 135.1 14.0 137.4 7.9 AD day 1, mmHg 9.7 3.3 10.5 3.8 AD day 4, mmHg 10.1 3.1 8.1 3.0* Mean improvement, mmHg -.4 3.4 2.4 5.2* Nu mb er of ob se rv at io ns da y 1 12.0 1.8 13.0 2.8 Number of observations day 4 12.5 1.7 12.0 1.8 p<0.05 As shown in Figure 4-7, gende r has an effect on estimation of SBP among subjects who are not taking HM (N =16). F emale hype rtensives that didn’t take medications for hype rtension (N = 7) were compare d to male hypertensive s that didn’t take medications for hy pertension (N = 9) using an independe nt samples t-test. A significant difference (p = 0.03) was found between the two gr oups using a two-tailed

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88 8.72 12.88 8.65 7.410 2 4 6 8 10 12 14MaleFemaleAbsolute Difference Day 1 Day 4 2.43 -0.4-1 -0.5 0 0.5 1 1.5 2 2.5 3HM Non-UsersHM Users HM Non-Users (N = 16) and HM User (N = 23)Mean Improvement Improvementtest. The mean improvement for hypertensives that did not take HM was 0.06 5.4 mmHg for males and 5.5 3.1 mmHg for females. This improvement is also interesting given the fact that similar findings occurred when comparing CE males and females. Refer to Table 4-7 for a description of hypotheses and major findings. Figure 4-6.Comparison of improvement in SBP estimation between HM nonusers and HM users. *p 0.05 by independent sample t-test. Figure 4-7. Gender effects on estimation of SBP among HM nonusers (N = 16). Female scores statistically different than male scores at p 0.05 level by independent sampled t-test.

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89 Table 4-7. Summary of major o utcome m easure s for ea ch hy pothesis Hyp othe sis Focus Outc ome mea sure An alysis method Re sults H1 TS (N = 39) Day 1 mean AD comp ared wit h d ay 4 me an AD Paired-sa mples t-test M ean A D D 1 = 1 0.1 mmHg M ean A D D 4 = 9 .3 mmHg MI = 0 8 mm Hg H2 CE (N = 15) & NCE (N = 24) Co mp are b oth groups mean imp rove me nt Inde pendent samples t-test MI CE = 2. 0 mm Hg MI NCE = 0. 04 mmHg H3 CE (N = 15) Day 1 mean AD comp ared wit h D ay 4 me an AD Paired-sa mples t-test Mean AD D 1 = 9.74 mmHg M ean A D D 4 = 7 .8 mmHg MI = 2 0 mm Hg *p = 0. 042 H4 BMI < 30 (N = 17) & BMI 30 (N = 22) Co mp are b oth groups mean improvement Inde pendent samples t-test MI BM I< 30 = 0.9 mm Hg MI BMI 30 = 0 7 mm Hg H5 M ales (15 ) & femal es ( 24) Co mp are b oth groups mean imp rove me nt Inde pendent samples t-test MI ma l es = 0 1 mm Hg MI f em al es = 1 2 mm Hg H6 Age < 48 (N = 15) & Age 48 (N = 24) Co mp are b oth groups mean improvement Inde pendent samples t-test MI ag e < 48 = 0 9 mm Hg MI age 48 = 0 7 mm Hg H7 HM non user (N = 16) & HM user (N = 13) Co mp are b oth groups mean improvement Inde pendent samples t-test MI HM nonuser = 2. 43 mmHg MI HM us er = 0. 4 mm Hg p = 0. 05 No te: TS = to tal sam pl e, C E = c ol leg e ed uca ted NC E = n onc ol leg e-e duc ate d, M I = mean improvement, HM = hy pertension medication, BMI = body mass index. Analysis of Covarianc e It is u seful to d etermine if there are an y c ovary ing fac tors that a re sign ificantl y related to mean imp rovemen t of estima ting SB P. A one-w ay betwee n subject s ANCOVA (analy sis of covariance) allows the investiga tor to remove the effect of a known covariate, thereby providing a method of statistical control. An ANCOVA was performed to examine the effects of ge nder and hy pertension medication use on the total

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90 sample mean improvement scores, covary ing out the effects of BMI and age. The corrected mod el was signifi cantly related to mean i mprovement in estimat ion of SBP between day s 1 and 4 (p = 0.05). The main effect of hypertension medica tion use was significantly r elated to mean improvement (p = 0.05), with nonusers of hy pertension medication having greater improvement (2.4 5.2 mmHg) than users of hy pertension medication (-.4 3.4 mmHg). The interaction betwe en hyperte nsion medication use and gende r was als o signif icantly related to mean i mproveme nt (p = 0.0 3). Thes e effe cts were seen after taking into account BMI a nd age. Both BMI (p = 0.5) and age (p = 0.9) were not significantly related to mean improvement scores. Reporting S ymptoms and Esti mating SBP Among th e total hy pertens ive samp le, 14 (36 %) parti cipants r eported sym ptoms associated with high BP. Reported sy mptoms included tenseness, flushing, and headache. A grea ter improvement (1.14 4.9 mmHg) was seen in the 14 subjec ts who reported symptoms associa ted with elevated BP compared to the 25 subjects who did not report s ymp toms (0.6 3.5 mmHg ). An ind epende nt samples t-test wa s perfor med to compare the mean improveme nt score s of subje cts who re ported e xperienc ing sy mptoms with those who did not. No significant differences we re found (t = -.38, df = 37, p = 0.71). Refer to Figure 4-8 for a description of this data. Among hype rtensives that do not take HM, 13 subjects reported not experiencing symptoms relating to their hig h BP levels and 3 reported experiencing symptoms relating to their high BP levels. The mean improvement of those subjec ts is shown in Figure 4-9. The mean improveme nt of subje cts who d id not take HM and re ported sy mptoms associated with high BP levels (N=3) improve d an average of 4.14 mmHg after training. Subjects who did not report symptoms associate d with their SBP and who were not using

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91 3 4 5 6 7 8 9 10 11 NoYesMean Absolute Difference Day 1 Day 4 2.03 4.14 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5Mean Improvement N = 16Mean Improvement no yesHMs (N = 13) improved an average of 2.03 mmHg after training. The small numbers of participants in each group and the uneven distribution of subjects per group make this comparison difficult and more inquiry is needed. Figure 4-8. Reporting of symptoms associated with high BP and SBP estimation. Figure 4-9.Reporting of symptoms among nonusers of HM (N = 16). High BP Estimation Because of the repeated measures design of the study, absolute differences can be computed for repeated measures of actual SBP and estimated SBP. A total of 1847 BP measurements/estimations were analyzed. Using SPSS, a filter variable was created by selecting only cases that were less than 140 mmHg (N = 1095). The mean AD across all

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92 days was c ompared between cases that we re < 140 mmHg compared with cases tha t were $ 140 mmHg. There were statistically significant differences be tween the two groups using an independent samples t-test (t = 4.13, df = 1845, p = 0.001). The mean AD across all day s for the $ 140 mmHg group of cases wa s 9.37 7.4 and the mean AD across all day s for the < 140 mmHg group of c ases was 8.0 6.7 mmHg. The less than 140 mmHg group of cases (N = 1095) had a mean AD on day s 1, 2, and 3, and 4 of 9.9 mmHg, 6.6 mmHg, and 8.8 mmHg, respe ctively. The g reater than or equal to 140 mmHg group of cases (N = 752) had a mean AD on day s 1, 2, and 3, and 4 of 10.0 mm Hg 8 .7 mm Hg a nd 9. 9 m mH g, re sp ec ti ve ly.

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93 CHAPTER 5 DISCUSSION AN D RECOMMENDATIONS All descr iptive an d analy tic resul ts that ad dressed each re search hyp othesis wi ll be discussed in this chapter. Conclusions and implications for clinical practice as w ell as recommendations for future researc h will also be provided. Discussi on of Resu lts This study was unique in its design a nd attempts to directly focus on hyp ertensiv es and pr ovide both phy siologi cal and s elf-aw arenes s feedba ck, espe cially using a repeated measures de sign and ambulatory BP monitoring. Similar studies have undertaken the task of determining the eff ects of feedback on BP estimation (Bar r et al., 1988; Cinciripini et al., 1979; Greenstadt et al., 1988; Luborsky et al., 1976). However, the present study is the first to examine the e ffects of biosituational feedback using ambulatory monitoring on the estimation of SBP in adult hypertensive persons. Prior studies were composed of normotensive, y ounger, male samples. I n addition, this study sought to uncover differe nces in e stimation of SBP amo ng a pop ulation of adult hypertensives a nd also between different sub-g roups of the sample. Hy pothesis 1 For hypothesis 1, hy pertensive subjects’ day 1 mean absolute difference betwee n actual and es tima ted S BP was compa red to t heir d ay 4 mean ab solu te dif ferenc e usin g a paired-samples t-test. The mean absolute differ ence on day 1 was 10.1 mmHg. The mean abs olute diff erence on day 4 was 9.3 mmHg. Th ese find ings indi cate tha t subjects

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94 were accurate in estimating their SBP within 10.1 mmHg on day 1 a nd that they improved an average of 0.8 mmHg from day 1 to day 4. These r esults were not statistica lly s ignific ant using a two-ta iled test (t = 1.09, df = 38, p = 0.28). These re sults occurred for several re asons. First, because there has be en limited research hy pertensive persons and estimation of SBP, it was unclear what, if any factors would have more influence on estimation of SBP. Therefore, data were collected that captured potential influencing factors. I n this study, education level, g ender, BMI, a ge, and hy pertension medication usage were examined to assess a ny differe nces between groups of hypertensives. I n testing hypothesis 1, the se factors were not accounted f or or controlled. However, the results of hy potheses 3 and 7 indicate that college educ ation and hypertension medica tion usage are important factors to conside r when training hyp ertensiv e person s to becom e more a ware o f their SB P. Th e m ea n e st im at ed SB P f or th e t ot al sa mp le wa s 1 37 .3 8 .6 mm Hg on da y 1 and 136.1 11.8 mmHg on day 4. It is interesting to note that while the mea n actual and mean estimated SBP were fairly similar on day 1 and da y 4, the standard de viation was not as similar. For example, the standard deviation on day 1 for actual and estimated SBP was 11.0 mmHg and 8.6 mmHg respec tively. The actua l variation in SBP was greater than the variation of e stimated SBP. On day 1, subjec ts were given their mean SBP level for the f irst study day This inf ormation w as give n to assist t he subjec t in having a better idea of where to start the estimation process. The data indicate that on the first study day subjects tended to estimate their SBP within a tight range of numbers and tended to stay within this r ange. Additiona lly, one estima te was hig hly correl ated with the immediately following e stimate. For example, using the SAS statistical software package, a mixed model procedure wa s performed to assess the relationship between one

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95 estimate and the ne xt. This rela tionship w as 0.80, in dicating that the tw o measur ements were hig hly correl ated. Th is means th at subje cts also te nded to g uess thei r SBP fai rly consiste ntly and cha nged th eir estim ation ba sed on some knowledg e/intuitio n. This finding has been seen in other studies (Br ondolo et al., 1999). Although subjects tended toward improving improved their mean absolute diffe rence between day 1 and day 4, the improveme nt was not s ignific ant. Hy pothesis 2 Because recent literature suggests that there are differences in health status and greater health disparities among CE versus NCE persons, educational level was treate d as a subgr oup and di vided into two cate gorie s; CE and NC E. Hy pothesis 2 compare d CE hypertensives with NCE hy pertensives to assess differences in their mea n improvement scores for day 1 and day 4. The mean improvement was calculated by taking the absolute value of the mean difference between day 1 and day 4 for each subject and then averag ing this b y th e total nu mber of s ubjects in that g roup. The re were no statisti cally significant differences in mean improvem ent between the two groups using an independent samples t-test. NCE hy pertens ives had s ignific antly more fa mily cardiov ascular disease (p = 0.05), were older (p = 0.05), a nd used more hy pertension medications (p = 0.05). The mean actual SB P for the CE group w as signi ficantly lower co mpared t o the NCE group on day 1; 132.8 mmHg and 139.6 mmHg, respectively (p = 0.05). Similarly, the mean SBP on day 4 wa s lower for the CE group, however not significantly (p = 0.108). These findings are not surprising consider ing that older age and lower educational level have been associated with higher B P and greater morbidity and poorer outcomes (de Gaudemaris et al., 2002).

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96 While the findings of the present study indicate that the educational groups were not significantly diff erent from one another in their ability to estimate their SBP, it was interesting to note that CE subjects had fairly good improvement (2.0 4.1 mmHg) after the training intervention. Because of this f inding, hypothesis 3 examined the eff ects of training on CE hype rtensives. Hy pothesis 3 For hypothesis 3, t he mean absol ute difference bet ween actual and estimated SBP on day 1 was c ompared to the mean absolute differenc e between actual and estimated SBP on day 4 among CE hypertensives. T he mean AD on day 1 was 9.7 3.4 mmHg and the me an AD on d ay 4 was 7.8 2.0 mmHg CE subjec ts were a ble to esti mate thei r actual SB P within 7.8 mmHg, a fter the training interve ntion. A sig nifican t decre ase was foun d in the me an AD fr om day 1 to day 4, sugg esting t hat CE hy pertens ive subje cts significantly improve d their accuracy in estimating their SBP after training (p = 0.04, one-tailed-test). These findings are not su rprising considering that educational leve l effec ts learni ng and o utcomes ( Myl lyk anga s et al., 1 995; Winkle by e t al., 1992 ). These findings are similar to published BP estimation research tha t found that subjects did not have g ood pred iction of t heir BP p rior to f eedbac k or train ing (B aumann & Leve nthal, 1985; Fahrenberg et al., 1995). I n addition, these findings support the results from feedback intervention ty pe studies that reported improvement in estimating SBP. Similarly to the cur rent stud y f indings, Lubo rsky et al., ( 1976) re ported th at subjec ts improved from 11.5 mmHg to 7.4 mmHg after a feedback intervention. In a study performed by Wizner, Gryg lewska, Gasowski, Kocemba, and Grodzicki (2003), hyper tensive subjects, compared with normotensives, were less aw are of norma l BP value s. The au thors con cluded t hat poor a warene ss of norm al BP val ues in

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97 hypertensives c ould be an important factor hindering better BP control. Furthermore, accord ing to the goals de lineated by H ealthy People 20 10, it is impo rtant for people to know their BP range and be able to state whether their BP was normal or hig h (Healthy People 2010, 2003). Therefore, 7.8 mmHg is a r easonably g ood level of accuracy considerin g it would be cl inically import ant if a subje ct could ass ess his/h er high SBP within 7.8 m mHg. Thi s finding supports the hy pothesis th at CE hy pertens ives dec rease their mean AD after training compa red to before training. While these results ar e promising, additional research is needed to test these findings, such as using a large r sample of CE hyperte nsives age-matched with equal number s of both genders and controlling for HM use. Gender analy sis was pe rformed to asses s mean impr ovement a mong mal e compare d to fema le CE subje cts. Gen der dif ferenc es were noted, as female C E hypertensives ( N = 9) improved 3.3 4.76 mmHg while the male CE hy pertensives actually g ot worse after the training, with a mea n improvement score of -0.09 1.2 mmHg. The difference betwe en the two gender g roups approached, but did not reach statistical significance (p = 0.07). Differ ences between males and fe males exist which are emotional, psyc hological, and phy siological and can affec t learning patterns (Asai et al., 2001 ; Hy man & Pav lik, 2001) In a recen t study health d isparitie s in relat ion to hyp ertensio n were e xamined. F emales w ith less ed ucation h ad almost a 100% incr ease in hypertension compar ed with females with more education (de Gaude maris et al., 2002). Potentially these fac tors may play a role in females having gr eater improvement over males. Clinical c haract eristic d iffere nces be tween the two gro ups were found as t he CE group w as thinne r than the NCE gro up; BMI = 29kg/ m 2 and 31.4 k g/m 2 respec tively

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98 (nonsig nifican t differ ence) a nd had low er mea n actual and estima ted SBP le vels (signif icant fo r day 1, p = 0.05 ). Similar to the tota l sample of hyp ertensiv e subjec ts, nonsign ificant t rends in s tandard deviatio ns of act ual and e stimated SB P were se en in both the N CE and CE g roups. On day 1, subjec ts in both g roups had less var iability in their estimation of their SBP compared with day 4. This occurrence, however, wa s not statistically significant. The findings of hy pothesis 3 are in line with research linking intervention success and health outcomes with education level. Hy pothesis 4 Hypothesis 4 assesses whe ther there are differe nces in mean improvement betwee n hy pertens ives with a BMI less tha n 30 compa red to hy pertens ives with a BMI great er than o r equal t o 30. Ther e were no sign ificant d iffere nces bet ween the BMI groups mean improvement scores, by independent samples t-test (t = 0.-16, df = 37, p = 0.88) It w ould seem possible th at peopl e with inc reased BMI who may potentia lly have elevated SNS activity would have more improvement in or accurac y in estimating their SBP. However, this did not occur. The mean improvement scor e of the BMI < 30 gro up w as 9 3 .9 m mHg and th e me an i mp rov eme nt sco re f or t he B MI $ 30 group was .7 4.9 mmHg. Therefore, on avera ge, subjects in both groups only improved 0.8 mmHg after training. The mean actual SBP for the BMI less than 30 group (N = 17) was g reater than the mean actual SB P of the B MI g reater than or e qual to 30 g roup of su bjects. T he BMI < 30 gro ups ’ me an a ctu al S BP w as 1 39. 5 on day 1 and 138 .2 o n da y 4. T he B MI $ 30 group had a mean actual SBP of 135.1 mmHg on day 1 and 134.5 mmHg on day 4. At first glance, these findings are surprising considering that a g reater BMI has been correlated with higher BP in sever al studies (Masuo, Mikami, Ogihara, & Tuck, 2000;

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99 Uehara, Miy azaki, Kanase, Sugano, & Toy o-Oka, 1996). However, a majority (85%) of the total sample took some type of medica tion, while 59% used antihyperte nsive medication regularly This probably acc ounts for the lower SBP levels in the BMI group. No differences between g roups may ha ve occurred for severa l reasons. First, the BMI $ 30 grou p had sig nifican tly m ore mal es than th e BMI < 30 gr oup (p = 0 .02). Thi s may have pla yed a pa rt in training and awareness of SB P patterns and estimation. As previous ly d escribe d, there were sig nifica nt differ ences a mong mal es compa red to females in the HM nonuse group with reg ard to mean improvement. Similarly, ther e were no nsignif icant tre nds in fem ales hav ing bett er improv ement tha n males in t he CE subgroup (p = 0.069). I t is clear that females improved gre ater than males in CE and HM nongroups. More research is nee ded to assess the impact of gender a nd BMI gr oups on improvement of estimating SBP. In a ddition, hy pertens ion medic ation use is probab ly a n importan t factor in whether people c an improv e the est imation of SBP. A lar ger sa mple size is needed to ass ess th e co var iat es h yper ten si on m edi cat io n us e, g end er a nd B MI. Inte res ti ngl y, su bj ect s wh o we igh ed m ore (BM I $ 30) had significantly more asthma (p = 0.05) and chronic pain (p = 0.05) compared to the thinner (BMI < 30) hypertensive subjec ts. These findings are similar to resear ch on BMI and hea lth status. People wh o weigh more and have g reater BMI ’s are a t grea ter risk f or devel oping he alth problems and high BP (Wizner et al., 2003; Uehara et a l., 1996). Hy pothesis 5 Hypothesis 5 sought to examine g ender differences in estimating SBP. An independent samples t-test was performed to compar e the mean improvement scores of male hyperte nsive subjects with female hy pertensive subjects. No significant differenc es

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100 were fo und (t = .752, df = 37, p = .45 7). The mean impr ovement o f the male hypertensives ( 0.1 4.4 mmHg) was not significantly different than the mean improvement of the female hy pertensives (1.2 4.5 mmHg). Refer to F igure 4-4 for a graph of gender dif ferences. When controlling for HM use between both g enders, the mean improvement for HM nonusers was 0.06 + 5.4 mmHg for males (N = 9) and 5.5 3.1 mmHg for females (N = 7). Using an independent samples t-te st, female hype rtensives that did not take medications for hype rtension were compared to male hy pertensives that did not take medications for hype rtension. A significant difference (p = 0.03) was found between the two gro ups using a two-ta iled test. The fe male HM no nusers w ere abl e to estima te their SBP within 7.4 mmHg after tr aining, while the male HM no nusers w ere abl e to estimate their SBP within 8.65 mmHg. The mean improvement for fema le HM nonusers was 5.5 mmHg. The interaction betwe en gender and HM use was sig nificant even af ter cova ry ing out th e effe cts of BM I an d age. These fi ndings a re not ne cessar ily surprising considering that male ge nder has been shown to be a predictor in lac k of awareness of hy pertension (Asai et al., 2001; Hy man & Pavlik, 2001). Hy pothesis 6 Hy pothesis 6 sought to compare two ag e grou ps of adul t hy pertens ives to examine differences in mean improvement. An independe nt samples t-test was performed to compare the mean improveme nt of hypertensive pe rsons less than 48 year s of age with hy pertensive persons greater t han or equal to 48 ye ars of age. There we re no significant differences in improvement of SBP estimation between the two groups of hypertensive pe rsons (t = 0.117, df = 37, p = 0.91). Refer to Fig ure 4-5 for an illustration of these findings. Both groups wer e similar in their improvement scores (0.9 mmHg for

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101 older hyper tensives and 0.7 mmHg for y ounger hy pertensives). This finding is not surprising given that the literature sug gests that there may be several ty pes of persons with elev ated SNS a ctivity includin g olde r and y ounger hyp ertensiv es and ob ese hypertensives. The mean actual SBP for the y ounger group was 130.8 mmHg for day 1 a nd 131.3 mmHg for day 4. The mean actual SBP for the older g roup was 140.9 mmHg for day 1 and 139.0 mmHg for day 4. The < 48 ye ars of age group ha d significantly lowe r actual SBP than the $ 48 years of age group on both day s 1 and 4 (p = 0.004 and p = 0.05 respectively by independent samples t-te st). This has also been shown in other studies and underscores the difference s between y ounger and older hy pertensives (Hy man & Pavlik, 2001). Hyman and Pavlik found similar r esults and reported that an age of a t least 65 year s accounted for the grea test proportion of risk for lack of control and aware ness of SB P among h ype rtensive s. When comparing the two age g roups, the young er hyper tensives were significantly more educated (p = 0.03) and had lower SBP levels on day 1 (p = 0.004) and day 4 (p = 0.0 5). I t is unclea r if these differe nces pla ye d a role i n the res ults; however, it is clear that education and SBP levels a re important in BP estimation. Among both age categ ories, 67% of youn ger subjects were HM users a nd 54% of the older subjects were HM users. Therefor e, HM use could have been a conf ounding factor in why some subjects improved and w hy others did not. B ecause of the potential importance of HM use in the ability to estimate SBP, hypothesis 7 soug ht to uncover any differences in mean improvement betwee n subjects who took HM medications compared with those who did not

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102 Hy pothesis 7 An independent samples t-test was performed to compar e the means of hypertensive pe rsons using HM (N = 23) to hy pertensive persons not using HM (N = 16). As Table 4-6 shows, the HM nonuser and HM user subjects we re similar in age, marital status, and education level. The HM nonuser subjects wer e more overweight, had the diagnosis o f hypertension lon ger, and had greater lev els of actual and estimat ed SBP compared with the HM Users. The HM nonusers mea n weight was 216 pounds and mean heig ht wa s 69.1 inch es. I n rev iewi ng t he lit erat ure o n wei ght a nd bod y m ass in dex, people with greater weig ht may have incr eased SNS activity and ther efore are speculated to possibly have more sig ns or symptoms related to SNS activation (Ma suo, Mkami, Itoh, & Tuck, 2000). I t is unclea r whethe r this af fects the ir ability to be more aware of their SBP. A significant difference wa s found between groups (t = 2.038, df = 37, p = 0.05) for a two-tailed test (p # 0.05). HM use continued to be significantly related to mean improvement even after covary ing out the effects of ge nder, BMI, and a ge. The mean improvement of the HM nonuser group (2.4 5.2 mmHg ) was significantly better than the group using HM (-.38 3.4 mmHg). These findings were observed e ven after perfor ming an A NCOVA, c ovary ing out t he effe cts of BM I an d age ( p = 0.05) These findings are not surprising considering the knowledge reg arding the main and residual effects of antihy pertensive medications. BP medications attempt to decrease BP by affecting pathway s in the body responsible f or BP control (e.g., RAAS, slow-calcium channe l, and bet a-rec eptors) Even tho ugh an tihy pertens ive medic ations ar e desig ned to be selective in lowering BP safely additional and/or side-effects of antihy pertension medicati ons are k nown to oc cur. Fo r example beta-b locking medicati ons are r eported to

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103 have adverse effects such a s bradyca rdia, sync ope, low BP, asthmatic attacks, congestive heart failure, hallucinations, loss of appetite, heada ches, nausea, weakness, and depression (Smith & Reyna rd, 1995). These adverse eff ects may impact the pote ntial for people with hyperte nsion to experience symptoms associate d with their high BP. It has been reported that adults who are obese h ave impaired adrenergic and baroreflex function (Grassi et al., 2000). It may be possible that obese hy pertensive persons may have signs or sy mptoms asso ciated w ith incre ased SNS a ctivity and/or B P elevati on, but this is unreported in the literature. Reporting of Sy mptoms There were also trends noted among subjects who reported sy mptoms associated with high BP versu s tho se sub jects who di d not report symptom s asso ciate d wit h high BP. Interestingly subjects who reported sy mptoms associated with high BP showed a trend toward greater a ccuracy before and after training and a trend toward greate r improveme nt in estima ting the ir SBP. Al though th ese find ings ar e not stati stically significant, it may be important to continue this inquiry into additional factors that may be related to estimation of SBP. For example, when controlling f or HM use, the mean improvement in subjects who reported sy mptoms and did not take HMs was 4.1 mmHg compared to 2.0 mmHg for HM users. These findings show promise in creating a model that may help distin guish pe ople who c ould be mo re easi ly tr ained to e stimate th eir SBP, however the sample size was small (N = 3) for the subjec ts who reported symptoms and did not take HMs. In future studies, it may be worthwhile to examine HM users and nonusers improvement after training sepa rately and c ontrol for reporting of sy mptoms.

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104 BP Varia bility There a re seve ral fac tors to co nsider w hen eva luating BP estima tion. Fir st, variability of BP is important beca use without fluctuations, patients have no comparison experiences to facilitate awareness of diff erent levels of BP. BP variability is influenced by both bio-situational and behaviora l factors, presumably through central modulation of autonomic drive to the heart and sy mpathetic blood vessels (Esler, 2000). People without hypertension or c irculatory disea se may not display great variations in BP or have symptoms that may be associated with SNS activation. Because the phy siological literature suggests that people with high B P may have fluctua tions in circulating hormones and changes in SNS activity it was important to evaluate people who are experiencing ty pical day-today life stress ors. Variability was a chieved in this study as subjects’ mean actual SBP on day 1 was 137.0 11.0 mmHg and 136.1 12.1 mmHg on day 4. This fin ding wa s similar to actual SBP data f rom 10 ra ndomly selecte d subject s in Dr. Yucha’s study that showed an average daytime rang e in SBP of 33.2 mmHg, ranging from a minimum of 19 to a maximum of 56 monthly (unpublished BP variability data, 2001). High BP Estimation When anal yzin g the re peated m easure ments and calcula ted scor es, subje cts estimate d their SB P within a ti ght ran ge of numbers a nd had littl e deviat ion compa red to the actual SBP measurements. Furthermore with a large increase in SBP level, one might imagine that potentially subjects may g et better in estimating their SBP. However, the opposi te was tr ue. As sub jects’ a ctual SB P got lar ger the y c ontinued t o estimate within the ir mean r ange a nd there fore the ir absolu te diffe rence s cores w ere extre mely high.

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105 Brondolo et al. (1999) found that higher or lower levels of BP did not account for the individual differences in the ability to estimate BP. In the prese nt study, among the total sample repeated measures data, estimation of SB P lower than 140 mmHg was signific antly better th an estima ting SBP g reater than or e qual to 140 mmHg. B ecause subjects estimated their SBP very close to their mean SBP, it was not surprising that when SBP levels were 140 mmHg or high er, subjects were significantly poorer estimators than the times when SBP was less than 140 mmHg (t = 4.13, df = 1845, p = 0.000). This may have oc curred for a number of re asons. First, subjects may ha ve not had any cues at all abou t their SBP and estimat ed their SBP based on the f irst few SBP readings and mea n score provi ded to them o n day 1. Other studi es found tha t BP estimation was better when subjects were provided w ith previous BP measurements (Barr et al., 1988; Brondolo et al., 1999; Cinciripini et al. 1979; Greenstadt et al., 1986; Luborsky et al., 1979). Alternatively they may have had cues of change s in BP, but not have been confident in estimating too much over or under their mean SBP level. I t may be prudent to perform a follow-up study to assess the impact of the training intervention without providing subjects their initial mean SBP levels and instead discuss with them their SBP variability and ave rage after the tra ining is completed. This may he lp them understand SBP variability a nd have more ability to estimate their high and low ranges and possibly improve overa ll accuracy Conclusions This study sought to examine the ef fects of an ambulatory BP, biosituational aware ness tra ining int erventi on on the a bility of hy pertens ive pers ons to estim ate their SBP. The fin dings of thi s study are similar t o studies that have ex amined bot h BP estimation and BP estimation with feedback. Among the fe edback intervention-ty pe

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106 studies t hat have been p erformed to d ate, all show ed an improv ement in BP discrimination after feedback (Ba rr et al., 1988; Brondolo et al., 1999; Cinciripini et al., 1979; Greenstadt et al., 1986; Luborsky et al., 1976;) and with a similar degree of improvement. This study was unique in that it assesse d adult hypertensives using ambulato ry BP monitor ing cou pled with b iosituatio nal selfaware ness tra ining to improve SBP estimation. The major findings of this study w ere four-fold. First, hy pertensives that were college-educated had statistically significant improvement in estimating their SBP after the training intervention (p = 0.04). Secondly hypertensive pe rsons not using antihy pertens ive medic ations impr oved at a statistica lly s ignific ant leve l compar ed to hypertensive pe rsons who used antihyper tensive medications (p = 0.05). Third, hypertensive f emales who did not take antihy pertensive medications improved significantly c ompared with hyper tensive males that did not take antihy pertensive medications (p = 0.03). Finally as actual SBP increased, estimation of SBP was not as accurate compared with less than 140 mmHg SBP levels (p =0.000). Implications for Clinical Practice In the clinical setting, it would be va luable if clinicians could teach patients how to estimat e and moni tor their BP while t hey are in th eir norma l environ ment. As pa tients become m ore know ledgea ble and r esponsib le reg arding their he althcar e choice s, it is important for clinicians to find alternative and innovative means to improve the ca re and outcomes of patients. Over the past several y ears, changes have oc curred in health care that have made pat ients more than mer e passiv e partic ipants of their he althcar e. Patien ts are much more willing and able to learn m ore about their health and well-being than previous generat ions (Str ohecker, 1999 ). Teaching peopl e about thei r BP and BP

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107 pattern s is an ef fective way to improve health o f patien ts and emp ower pe ople with hypertension to have more control over their own life and health (He althy People 2010, 2003). Th is study provides evidenc e that so me hy pertens ive pers ons can le arn to estimate their SBP at least within an average of 7.4 mmHg and that most patients can at least be trained to have mo re awa reness o f their me an/rang e BP info rmation a nd estimat e their SBP within an average of 9.2 mmHg This intervention may also be va luable for patients who need to learn about their SBP patterns. All patients with hy pertension should be a ware of their BP p atterns; patient s who are unmotivate d to partic ipate in th eir treatment and/or are unsure of their B P patterns many be nefit from learning more about their BP p atterns a nd BP var iability Althoug h the pre sent study did not tes t this clai m, this intervention may improve patients’ motivation to seek or continue treatment. More research examining outcomes and SBP estimation is needed to c onfirm this assertion. During and after the study it was clear that some subjects were surprised tha t their BP lev els were as high as they were. In addition, the majority of subje cts whose BP levels were outside of the normal range expressed the need to visit their healthcare provider. Some subjects reported visiting their healthcar e provider and switching/adding medications because of the knowledge of their actual SBP readings over a n extended period of time. It was also valuable f or subjects to obtain the 4-day print-out of the results of the ambul atory BP monitor ing ses sions. Subje cts were gener ally excited to participate and receive the print-out to bring to their healthcare provider. Althoug h the find ings show ed sign ificant i mproveme nt for ce rtain sub jects, it should be n oted that this improv ement, a lthough signific ant, was relative ly s mall. Because participants were only aware of their SBP within approximately 7-8 mmHg after training, the findings should not be used to solely treat or directly monitor SBP.

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108 However, the findings of this present study could be used to assist nurses and other healthcare providers in teaching patients about their BP patterns and variability and moti vatin g patie nts t o adhe re to p rescri bed tre atmen ts. W hile t his re search is pro misi ng, more inqu iry is neede d with lar ger sa mples an d focuse d inquiry to see if p eople wit h hyp ertensio n can impr ove their aware ness of t heir hig h BP episo des afte r partic ipating in ambulato ry BP and bio situationa l feedba ck trai ning an d if this tr aining w ill ultimate ly improve h ealthca re outco mes. Recommendations for Future Research A limi tatio n of th is stu dy was t hat t he sa mple s ize wa s rel ative ly small to an aly ze discrete differe nces amo ng gr oups of sub jects. I t was rea lized durin g the da ta analy sis phase tha t there w ere dif ferenc es betwe en ge nders am ong the CE and HM g roup. While the subg roups we re fair ly e venly distribut ed, the sm all numbe r of par ticipants in the CE group ma de it diff icult to exa mine discr ete dif ferenc es in ge nder amo ng the g roup of CE hypertensives. The refore, a largescale study tha t includes adult college-educated hyp er te ns iv es t ak in g i nt o a cc ou nt HM us ag e a nd ge nd er i s r ec om me nd ed A dd it io na ll y, because HM use se ems to be s uch an imp ortant fa ctor in SB P estimatio n, a larg e-scal e study examining hy pertensive adults who take and do not take antihy pertensive medicati on is also r ecommen ded. Alth ough th is study consiste d of a re latively small group o f hy pertens ive adult s (N = 39) it provi des usef ul informa tion that he lps elucid ate factors that are related to and important in assisting hypertensive pe rsons to be more aware of their S BP level s. Prior to this rese arch inq uiry these f actors w ere lar gely unknown and mostly speculative. Another limitation of the study is that subjects wer e given baseline information about their actual SBP prior to day 1 (pretraining). Actual SBP information wa s

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109 provided to the subjects because it was thought that subjects may need more information to help them make a guess about their SBP level. While it was true that this information did assist subjects in understanding how to estimate their SBP level, it may be more useful to give sub jects bro ad infor mation a bout SBP an d keep the m totally blinded to their ac tual SBP in formatio n until aft er the p retrain ing day Providing this knowle dge to them, whil e useful to the subj ects in un dersta nding the ir SBP and how to esti mate thei r SBP, may have limited the amount of impr ovement that was captured in this intervention between day s 1 and 4. It is recommended to only provide broad SBP range information and to keep the subjects totally blinded to their actual SBP during the pretraining pha se. This research study provides support for using feedback me thods to improve the ability to estimate BP in certain populatio ns, especially hy pertensives who are borderline hypertensives or new ly diagnosed and are not t aking HMs, and suggests that BP awareness may be improved in some people using feedbac k methods. However, the limited number of studies testing feedback methods on hy pertensives suggests that more research is needed to further a ssess the effects of BP aware ness feedback training among this gro up. Resea rch is als o neede d to eval uate clin ical outc omes of B P aware ness training such as B P control, patient mo tivation a nd adher ence wi th medica l treatme nt, co st -e ff ec ti ve ne ss a nd mo rb id it y an d m or ta li ty.

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110 APPENDIX A PRE-/POSTTR AIN ING SBP ESTI MATI ON FORM ID#___________ University of Flo rida College of Nursing SBP Estimation Study Pre-/Posttraining SBP Estimation Form Category Systoli c BP (m mHg) Optimal Less than 120 Normal 121-129 High-Normal 130-139 Stage 1 140-159 Stage 2 160-179 Stage 3 180 or greater Instr uctions: Each time the BP cu ff start s to infla te: Write the time in the space provided Circle an SBP category that correspond s to your estimated SBP Estimate your SBP and write it in the spac e provided Time SB P categ ory Estimated SBP Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r Less than 120 121-129 130-139 140 -159 160-179 18 0 or greate r

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111 APPENDIX B SBP ESTI MATI ON STUDY TRAI NIN G FORM ID# _______ University of Flo rida College of Nursing SBP Estimation Study Trainin g Form Category Systoli c BP (m mHg) Optimal Less than 120 Normal 121-129 High-Normal 130-139 Stage 1 140-159 Stage 2 160-179 Stage 3 180 or greater Instr uctions: Each time the BP cu ff start s to infla te: Write the time in the space provided Estimate your SBP and write it in the spac e provided Fill out the Self-Aw arenes s checkl ist After y our BP ha s been me asured, look at th e LCD screen on the BP m onitor an d write down your ac tual SBP in the space provided Time Esti mated SBP Actual SBP Self-Aw arenes s Checklis t: Circle Ye s or No f or each item **Curre nt: Laughing Yes No **Curre nt: Headache Yes No Frustrated Yes No Sweaty Hands Yes No Excited Yes No Tense Stomach Yes No Tense Yes No Fast Pulse Yes No Angry Yes No Tingl ing in face, ar ms or l egs Yes No Rushed Yes No Shortness of Bre ath Yes No Content Yes No Cold Hands Yes No Annoyed Yes No Warm Hands Yes No Smiling Yes No Happy Yes No Walking Yes No Loca tion at Hom e Yes No Running Yes No Location at Work Yes No Standing Yes No Location Outdoors Yes No

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112 Strenuous Activity Yes No **Within pri or 15-min utes: Using Caffeine Yes No Relaxing/Nonstrenuous Activity Yes No Using Alcohol Yes No Ly ing Down Yes No Using Tobacco Yes No Sitting Yes No Interpersonal I nteraction: Yes No Standing Yes No Positive Yes No Eating Yes No Negative Yes No Other Ac tivity : Yes No Neutral Yes No *Adapted from Barr, Pennebaker and Watson (1988), Brondolo, Karlin, Alexander, Bobrow and Schw artz (199 9), Gellm an et al (1990), JNC VI ( 1997), a nd Lub orsky et al. (1976).

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113 APPENDIX C SBP ESTI MATI ON STUDY TRAI NIN G FORM University of Flo rida College of Nursing SBP Estimation Study Demographic Data Sheet ID # _______________ Age _____ y ears D.O.B. _-_ _-_ Gender: 1.) Male 2.) Fema le Vetera n Status: 1.) Yes 2.) No Race 1.) NonHispanic White 2.) Hispa nic White 3.) Hispanic Black 4.) Black or African-Amer ican 5.) Asian 6.) I sland Pac ific 7.) Other Education 1.) Less than 7 y ears 2.) Junior high school (grades 7-9) 3.) Some high school (grade 10-11) 4.) Hig h school g raduate 5.) Some college or technical school 6.) Colleg e grad uate 7.) Graduate school (master’s deg ree or bey ond) Marital Status 1.) Married 2.) Never married 3.) Widowed 4.) Separated 5.) Divorced

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114 Height _ _cm Weight _ kg Length of time since diag nosis of hyperte nsion: 1.) Less than 5 y ears 2.) 5-10 yea rs 3.) 11-20 yea rs 4.) 21 year s or more

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115 APPENDIX D HEAL TH HI STORY FOR M ID#_____ University of Flo rida College of Nursing SBP Estimation Study Health History F orm 1.) Yes No Has a doctor ever told y ou that you have hig h blood pressure? 2.) Yes No Do you take medic ations for high blood pressure? 3.) Yes No Do you experience symptoms associated with y our high blood pressure? 4.) I f so, list th e sy mptoms: _______________________________________________________________________ _______________________________________________________________________ 5.) Yes No Has a doctor ever told y ou that you have he art disease? 6.) Yes No Have you e ver had a heart attack? 7.) Yes No Ha ve you ha d c ar di ac su rg er y? 8.) Yes No Do you have a cardiac pacemaker ? 9.) Yes No Have you e ver had a stroke? 10.) Yes No Ha ve you ha d c ar ot id ar te ry s ur ge ry? 11.) Yes No Has y our docto r ever told y ou that y ou had an aneury sm? 12.) Yes No Have you e ver had heart failure? 13.) Yes No Have y ou ever h ad an a bnormal E KG or irr egular heart r hyt hm? 14.) Yes No Do y ou have D iabete s? 15.) Yes No Do you hav e asth ma or di fficu lty breat hing? 16.) Yes No Do you suffer from chronic pain? 17.) Yes No Do you have pulmona ry, liver, or kidney disease? 18.) Yes No Do y ou have c ancer or tumors? 19.) Yes No Do y ou have th yr oid probl ems? 20.) Yes No Do y ou curre ntly smoke tob acco or use tobac co produ cts? 21.) Yes No Have y ou smoked t obacco or used to bacco p roducts i n the past ? 22.) Yes No Do y ou drink a lcoholic bevera ges? 23.) Yes No Do y ou drink c affei nated be verag es? 24.) Yes No Has y our docto r ever told y ou that y ou have h igh cho lesterol ? 25.) Yes No Do you exercise mor e than one hour per week? 26.) Yes No Are you c urrently ta king any prescription or nonprescription medicati ons?

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116 Name of Medication Dosage Frequency Prescribed Taken as Prescribed? (Yes/No /Sometimes ) Have y ou or any of y our blood r elatives (y our pare nts, broth ers, siste rs, uncle s, aunts, cousins, or children) ever had: 27.) Yes No Heart attack 28.) Yes No High blood b ressure 29.) Yes No Stroke 30.) Yes No Diabetes 31.) Yes No High cholesterol

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125 Vrijkotte, T., van Doornen, L., & de Geus, E. (2000). Effects of work stre ss on ambulatory blood pressure heart rate, and heart ra te variability. Hypertension, 35 880-886. Winkleby, M., Jatulis, D., Frank, E., & Fo rtman, S. (1992). Socioeconomic status and health: How education, income, and occupation contribute to risk fa ctors for cardiovascular disease. American Journal of Public Health, 82 (6), 816-20. Winkleby M., Kra emer, H. Ahn, D., & Var ady A. (1998 ). Ethnic and socio economic differences in cardiovascular dise ase risk factors: Findings for wome n from the third national health and nutrition examination survey, 19881994. Journal of the American Medi cal Associat ion, 280 (4), 1989-90. Winnicki, M., Canali, C., Mormino, P., & Palatini P. (1997). Ambulatory blood pressure mon ito rin g e dit ing cr ite ria : is sta nd ar diz at ion ne ed ed ? American Journal of Hypertension, 10 (4 Pt. 1), 419-27. Wizner, B., Gryg lewska, B., Gasowski, J., Kocemba, J., & Grodzicki, T. (2003). Normal blood pressure values as perce ived by normotensive and hy pertensive subjects. Journal of Human Hyper tension, 17 (2), 87-91. Wright, C. & Ang us, J. (1999) Enhanc ed total periphe ral vasc ular re sponsiven ess in hypertension ac cords with the amplifier hy pothesis. Journal of Hypertension, 17 1687-1696. Young, L., L angford, M., & Blancha rd, E. (1976). Effect of opera nt conditioning of heart rate on plasma rennin activity Psychosomatic Medicine, 38 (4), 278-281. Yucha, C. B., Clark, L., Smith, M., Uris, P., L aFleur, B., & Duval, S. (2001). The e ffect of biofeedback in hy pertension. Applied Nursing Research, 14 (1), 29-35. Zanchetti, A., Crepaldi, G., Bond, G., Gal lus, G., Veglia, F., Ventura, A., Mancia G., Baggio, G., Sampieri, L ., Rubba, P., Collatina, S., & Serrotti, E., on behalf of the PHYLL IS study group. (2001). Sy stolic and pulse blood pressures (but not diastolic blood pre ssure an d serum c holester ol) are associa ted with a lteratio ns in carotid intima-me dia thick ness in th e modera tely hyp erchole sterolae mic hypertensive pa tients of the plaque hy pertenion lipid lowering Italian study Journal of Hypertension, 19 79-88.

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126 BIO GRAPHI CAL SK ETCH Sandra Wolfe Citty was born in Parsippa ny, New Jersey She received her Bachelor of Science in Nursing degree in 1995 from the University of Miami School of Nursing, Coral Gables, Florida. Upon completion of he r bachelor’s degree Sandra worked as a regi stere d nurs e in th e area of cardio vascu lar nu rsing. After w orkin g as a regi stere d nurs e for t hree years i n cardi ovasc ular n ursin g, Sandra obtained her master’s degr ee in nursing from the University of Miami School of Nursing in 1998. Af ter comp letion of h er deg ree in nu rsing, w ith specia lization in f amily advanced practice nursing, she became board certified by the American Nurse’s Credentialing Center as a Family Nurse Practitioner and was licensed as a n Advanced Registered Nurse Practitioner. During this period, Sandra was active as an adjunct professor of nursing and continued in clinical nur sing practice. In 1999, Sandra returne d to the academic arena as a doctoral student at the Un iv er si ty o f F lo ri da C ol le ge of Nu rs in g. Du ri ng th e c ou rs e o f h er do ct or al st ud y, Sandra worked as a researc h assistant in the College of Nursing’s Offic e for Research Support an d was awa rded a 2ye ar, pre doctora l nurse f ellowship at the Nor th Florida/South Georgia Veteran’s He alth System. Additionally Sandra has been funded by Si gma The ta Tau I nternat ional Nur sing Ho nor Socie ty, Alpha The ta chapt er, to he lp offset costs associated with her doctoral rese arch. During the last two y ears of her doctoral work, Sandra was mentored by Drs. Maude Rittman and Caroly n Yucha during her position as a predoctoral nurse fellow. As a doctoral student, research assistant, and

PAGE 134

127 predoctoral nurse fellow, she has had valu able experiences in learning about veter an’s healt h iss ues, V A reso urces, grant w riti ng, pro posal devel opmen t, in strum ent te stin g, subject recruitment, data management a nd analysis, and publishing Sandra has published a manuscript in the Journal of Professional Nursing and has a manuscr ipt (in review) in the Journal of Applied Psychophysiology and Biofeedback Sandra has also presented posters at various regional, na tional, and international research confe rences. Sandra w ill grad uate in Ma y of 2003 with her Ph.D. in nursing and minor area in psychology She plans to continue her work in the field of nursing as a researcher, educator, and clinician.


Permanent Link: http://ufdc.ufl.edu/UFE0000663/00001

Material Information

Title: Ambulatory blood pressure biosituational feedback and systolic blood pressure estimation
Physical Description: Mixed Material
Language: English
Creator: Citty, Sandra Wolfe ( Dissertant )
Carolyn B. Yucha ( Thesis advisor )
Rittman, Maude ( Reviewer )
Stechmiller, Joyce ( Reviewer )
Berg, Keith ( Reviewer )
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2003
Copyright Date: 2003

Subjects

Subjects / Keywords: Department of Nursing thesis, Ph.D
Blood Pressure Determination   ( msh )
Blood Pressure monitoring, Ambulatory   ( msh )
Hypertension   ( msh )
Research   ( msh )
Dissertations, Academic -- UF -- College of Nursing -- Department of Nursing
Blood Pressure -- Physiology   ( msh )
Systole -- Physiology   ( msh )

Notes

Abstract: In an age of technological advances and medical breakthroughs, hypertension continues to be a devastating threat throughout the United States and worldwide. From 1987 to 1997, the death rate from high blood pressure increased by 13.1%. Difficulties in detection and treatment exist because hypertension is a relatively silent disease, for which patients are often asymptomatic and are feeling well. Because of the lack of observable symptoms associated with high blood pressure, patients with hypertension often have difficulty prescribing meaning to their disease threat or treatment requirements. The primary purpose of this research was to determine if subjects with hypertension can improve their awareness of their systolic blood pressure after participating in the ambulatory blood pressure and biosituational self-awareness training intervention. A repeated measure, pretest/posttest design was used for this study. Thirty-nine adult hypertensive subjects participated in the study. There were no significant differencesamong the group of hypertensives after training compared to before training, using a paired samples t-test. There were, however significant differences in improvement of estimating SBP among the subgroup of college-educated hypertensives (p = 0.04) and between the groups who used and did not use antihypertensive medications (p = 0.05). Hypertensives who did not take medications showed significant improvement compared to antihypertensive medication users. This study provides support for using feedback methods to improve the ability to estimate BP in certain populations, specifically college educated hypertensives and hypertensives who are not taking antihypertension medications, and suggests that BP awareness may be improved in selected people using feedback methods.
Subject: ambulatory, awareness, blood, estimation, hypertension, pressure
General Note: Title from title page of source document.
General Note: Includes vita.
Thesis: Thesis (Ph. D.)--University of Florida, 2003.
Bibliography: Includes bibliographical references.
General Note: Text (Electronic thesis) in PDF format.

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0000663:00001

Permanent Link: http://ufdc.ufl.edu/UFE0000663/00001

Material Information

Title: Ambulatory blood pressure biosituational feedback and systolic blood pressure estimation
Physical Description: Mixed Material
Language: English
Creator: Citty, Sandra Wolfe ( Dissertant )
Carolyn B. Yucha ( Thesis advisor )
Rittman, Maude ( Reviewer )
Stechmiller, Joyce ( Reviewer )
Berg, Keith ( Reviewer )
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2003
Copyright Date: 2003

Subjects

Subjects / Keywords: Department of Nursing thesis, Ph.D
Blood Pressure Determination   ( msh )
Blood Pressure monitoring, Ambulatory   ( msh )
Hypertension   ( msh )
Research   ( msh )
Dissertations, Academic -- UF -- College of Nursing -- Department of Nursing
Blood Pressure -- Physiology   ( msh )
Systole -- Physiology   ( msh )

Notes

Abstract: In an age of technological advances and medical breakthroughs, hypertension continues to be a devastating threat throughout the United States and worldwide. From 1987 to 1997, the death rate from high blood pressure increased by 13.1%. Difficulties in detection and treatment exist because hypertension is a relatively silent disease, for which patients are often asymptomatic and are feeling well. Because of the lack of observable symptoms associated with high blood pressure, patients with hypertension often have difficulty prescribing meaning to their disease threat or treatment requirements. The primary purpose of this research was to determine if subjects with hypertension can improve their awareness of their systolic blood pressure after participating in the ambulatory blood pressure and biosituational self-awareness training intervention. A repeated measure, pretest/posttest design was used for this study. Thirty-nine adult hypertensive subjects participated in the study. There were no significant differencesamong the group of hypertensives after training compared to before training, using a paired samples t-test. There were, however significant differences in improvement of estimating SBP among the subgroup of college-educated hypertensives (p = 0.04) and between the groups who used and did not use antihypertensive medications (p = 0.05). Hypertensives who did not take medications showed significant improvement compared to antihypertensive medication users. This study provides support for using feedback methods to improve the ability to estimate BP in certain populations, specifically college educated hypertensives and hypertensives who are not taking antihypertension medications, and suggests that BP awareness may be improved in selected people using feedback methods.
Subject: ambulatory, awareness, blood, estimation, hypertension, pressure
General Note: Title from title page of source document.
General Note: Includes vita.
Thesis: Thesis (Ph. D.)--University of Florida, 2003.
Bibliography: Includes bibliographical references.
General Note: Text (Electronic thesis) in PDF format.

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
System ID: UFE0000663:00001


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AMBULATORY BLOOD PRESSURE BIOSITUATIONAL FEEDBACK
AND SYSTOLIC BLOOD PRESSURE ESTIMATION















By

SANDRA WOLFE CITY


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA


2003















This dissertation is dedicated to my husband and children,
Jeff, Meghan, and Matthew;
in loving memory of Eric A. Wolfe;
and to my three wonderful families,
the McGrogans, the Wolfes, and the Cittys.
Thank you to Jeff for being a wonderful friend, husband, and father.
Thank you to Meghan and Matthew for being the best little researchers,
data collectors, and children in the world.
Thank you to my mom, Liz, for helping with babysitting and grandma things.
Thank you to my sister, Susan, for her support through this process.
I love you all very much!
Thank you, God!















ACKNOWLEDGMENTS

I gratefully acknowledge the assistance of my dissertation chairperson, Carolyn

Yucha, PhD, for her mentoring, guidance, humor, encouragement, patience, and wisdom

throughout the course of my 4 years at the University of Florida.

I gratefully acknowledge the support of the University of Florida College of

Nursing, UF College of Nursing Office for Research Support, N. Florida/S. Georgia VA

Health System, and Sigma Theta Tau Alpha Theta Chapter International Nursing Honor

Society for partial funding of this project.

I am extremely grateful to Maude Rittman, PhD for her guidance and mentoring

during my Predoctoral Nurse Fellowship at the Gainesville VAMC. I gratefully

acknowledge Ms. Susan Nadeau and the staff at the Brain Rehabilitation Research Center

and Rehabilitation Outcomes Research Center for their assistance with acquiring research

office space and subject recruitment. I also would like to extend my deepest appreciation

to my dissertation committee members-Maude Rittman, PhD, Joyce Stechmiller, PhD,

and Keith Berg, PhD-for their contributions and support of this project.















TABLE OF CONTENTS

page

ACKNOWLEDGMENTS ................. .......................... iii

ABSTRACT ................ ................................... vi

CHAPTER

1 INTRODUCTION .......................................... 1

Definition and Scope of the Problem ................................... 1
Problem Statement ........... ....................................... 7
Purposes of the Study .......................................... 8
Hypotheses ....................................... ............ 9
D efinitions of Term s ................................. ............. 9
Assumptions..................................................... 1
Limitations ................. .. .................... ............. 11
Significance of the Study ............... ........................ 11

2 REVIEW OF LITERATURE ................ ..................... 13

Theories of Hypertension Development ............................ 13
Systolic Hypertension ................ .......................... 25
Issues Surrounding the Treatment of Hypertension .......................... 26
Biosituational Factors Associated with High BP ............................ 31
BP Awareness and Estimation ............... ....................... 38
Educational Level and Health Disparities ................................. 49
Ambulatory BP Monitoring ............... ......................... 50
Summary ............... ............................ .52

3 PROCEDURES AND METHODS ..................................... 53

Research Design ................................................... 53
Population and Sample .............. .................... ......... 53
Inclusion and Exclusion Criteria ................ ................... .. 55
Setting ...........................................................56
Research Variables and Instruments .................................. 56
Study Protocol and Procedures ...................................... 63
Methods of Statistical Analyses .................. .................... 68











4 RESULTS ........................................... ............. 71

Descriptive Results ................. ............................ 71
Analytic Results for Hypotheses .................................... 75
Hypotheses ............ ............................................ 78

5 DISCUSSION AND RECOMMENDATIONS ............................ 93

Discussion of Results .......... ................... ........... 93
Conclusions ......... .... ..................... .... ......... 105
Implications for Clinical Practice ................. ................... 106
Recommendations for Future Research .............................. 108

APPENDIX

A PRE-/POSTTRAINING SBP ESTIMATION FORM ...................... 110

B SBP ESTIMATION STUDY TRAINING FORM ....................... 111

C SBP ESTIMATION STUDY TRAINING FORM ....................... 113

D HEALTH HISTORY FORM ......................................... 115

REFERENCES ............. .......................................... 117

BIOGRAPHICAL SKETCH ............................................ 126
























v















Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy

AMBULATORY BLOOD PRESSURE BIOSITUATIONAL FEEDBACK
AND SYSTOLIC BLOOD PRESSURE ESTIMATION

By

Sandra Wolfe Citty

May 2003

Chair: Carolyn Yucha
Major Department: Nursing

In an age of technological advances and medical breakthroughs, hypertension continues

to be a devastating threat throughout the United States and worldwide. From 1987 to

1997, the death rate from high blood pressure increased by 13.1%. Difficulties in

detection and treatment exist because hypertension is a relatively silent disease, for which

patients are often asymptomatic and are feeling well. Because of the lack of observable

symptoms associated with high blood pressure, patients with hypertension often have

difficulty prescribing meaning to their disease threat or treatment requirements. The

primary purpose of this research was to determine if subjects with hypertension can

improve their awareness of their systolic blood pressure after participating in the

ambulatory blood pressure and biosituational self-awareness training intervention. A

repeated measure, pretest/posttest design was used for this study. Thirty-nine adult

hypertensive subjects participated in the study. There were no significant differences

among the group of hypertensives after training compared to before training, using a









paired samples t-test. There were, however significant differences in improvement of

estimating SBP among the subgroup of college-educated hypertensives (p = 0.04) and

between the groups who used and did not use antihypertensive medications (p = 0.05).

Hypertensives who did not take medications showed significant improvement compared

to antihypertensive medication users. This study provides support for using feedback

methods to improve the ability to estimate BP in certain populations, specifically college

educated hypertensives and hypertensives who are not taking antihypertension

medications, and suggests that BP awareness may be improved in selected people using

feedback methods.















CHAPTER 1
INTRODUCTION

This chapter introduces concepts that are under investigation including the

significance of hypertension, problems with detection and treatment of high blood

pressure (BP), factors associated with dismal treatment rates, potential manifestations or

factors associated with high BP levels, and estimation of BP. This chapter will describe

the definition and scope of the problem, the main research problem to be investigated,

and the significance of the study. The definition of major terms, assumptions, and

limitations will also be described.

Definition and Scope of the Problem

Hypertension is defined as systolic BP (SBP) of 140 mmHg or greater, diastolic

BP (DBP) of 90 mmHg or greater, or taking antihypertensive medication. In the United

States, people with hypertension comprise a rapidly growing subset of the population.

Approximately 50 million Americans have high BP. High BP was the primary cause of

death for 44,435 Americans in 1998 and contributed to about 210,000 deaths (American

Heart Association [AHA], 2003b). Approximately 95% of people with hypertension

have essential (or primary) hypertension, for which no clear cause can be identified.

From 1987 to 1997, the death rate from high BP increased by 13.1% (AHA, 2000).

Treatment of hypertension continues to be plagued by dismal statistics in that only 27.4%

of Americans with high BP are adequately controlled on medication (AHA, 2003a).







2

Elevated systolic BP (SBP) specifically has been associated with increased

morbidity and mortality, especially in the older population. Prospective studies have

shown that there is a strong, continuous, graded, independent association between SBP

and the risk of coronary heart disease, stroke, and end-stage renal disease (He &

Whelton, 1999). Additionally, data from the National Health and Nutrition Examination

Survey (NHANES) III found that isolated systolic hypertension was the most frequent

subtype of uncontrolled hypertension, especially in subjects over 50 years of age

(Franklin, Jacobs, Wong, L'Italien, & LaPuerta, 2001). The incidence and severity of

complications increase with the duration and severity of hypertension (Kaplan, 1998;

Lackland, 2000). Because of this, it is crucial to identify and treat high BP, and

specifically high SBP, in order to reduce the risk of advanced cardiovascular disease and

its associated morbidity and mortality.

Inadequate adherence to antihypertensive therapy is a major challenge and

contributes to elevated BP levels in two-thirds of all patients with hypertension (JNC VI,

1997). One of the major obstacles in the diagnosis and treatment of hypertension is that

it has a very insidious course, which the patient often fails or refuses to recognize

because he or she may continue to "feel good." Noncompliance with antihypertensive

therapy has been cited as the major cause of treatment failure (AHA, 2003c).

Noncompliance is a multi-faceted issue that results from varying behavioral,

social, logistical, economic, and practical factors (Miller, Hill, Kottke, & Ockene, 1997).

Failure to comply with prescribed medication regimens or other therapies can affect

patients' health adversely as patients may fail to improve, worsen, or relapse.

Compliance not only affects the immediate patient but the entire United States health

care system and economy. Noncompliance accounts for 100 billion dollars in health care







3

and productivity costs in the United States. The costs of hospitalizations and practitioner

visits caused by noncompliance account for 8.5 billion dollars annually (Task Force for

Compliance, 1994).

Several factors have been associated with antihypertensive adherence patterns

including whether or not symptoms affect daily life or work, family history of

hypertension, household composition, perceived threat of complications, and perceived

need and perceived effectiveness of medications (McLane, Zyzanski, & Flocke, 1995;

Meyer, Leventhal, & Gutmann, 1985). Because hypertension is generally thought of as

an asymptomatic disease and due to the lack of definitive symptoms associated with high

BP, it can be difficult for patients to adequately prescribe meaning and importance to

their disease process and treatment options (McLane et al., 1995). If high BP were

associated with observable symptoms, it may be possible to improve early recognition of

the disease, improve its treatment compliance and improve outcomes.

Over the past several years, more attention has been paid to preventive health

care and patients have been viewed more in terms of being healthcare consumers and less

as being passive participants of the healthcare process. Noncompliance in the patient

with hypertension comes in the face of growing consumer empowerment among patients

(Skelton, 1997). More than ever, people are trying to improve their health by

participating in their care (Roter, Stashefsky-Margelit, & Rudd, 2001). In addition to

pharmacologic therapy, biofeedback therapy has been used successfully to assist people

in treating and preventing major health problems, such as hypertension, chronic pain, and

anxiety (Fernandez & Beck, 2001; Knost, Flor, Birbaumer, & Schugens, 1999; Lal et al.,

1998). Biofeedback therapy has been used successfully in both research and clinical

settings to lower BP in hypertensive patients (Lal et al., 1998; Yucha et al., 2001). These









therapies would be strengthened if patients were more aware of their high BP or if they

had symptoms associated with high BP that could be coupled with therapy. Healthy

People 2010 identified goals to advance the prevention, detection, and treatment of

hypertension, stroke, and heart disease. To increase public attention, awareness, and

treatment, goal number 12-12 states that there "should be an increase in the proportion of

adults who have had their BP measured within the preceding 2 years and can state

whether their BP was normal or high" (Healthy People 2010, 2003).

As patients with hypertension strive to become more involved in their healthcare

decisions, treatments need to be found that focus on the patient as the manager of his/her

own health. High BP is a phenomenon that generally is not associated with specific

symptoms or signs (AHA, 2003c). Because of this, patients with hypertension often have

difficulty understanding the threat of the disease or the treatments required to manage the

disease. In disorders with observable symptoms, such as diabetes mellitus, congestive

heart failure or seizures, patients may be more motivated to seek and continue treatment.

Little is known about the extent to which hypertensive patients are aware of their

high BP; however, several research studies and clinical experiences have shown that

people can be more aware of their BP levels after different types of feedback training. If

patients were aware of their high BP episodes, better-tailored treatment modalities may

be developed and adherence to therapeutic treatment may be improved resulting in better

patient outcomes. For example, biofeedback or relaxation therapies could be used to

assist patients in lowering their BP during episodes of high BP.

While there is continued controversy over whether there are definitive symptoms

associated with BP, it is generally believed that most patients with hypertension cannot

accurately tell if their BP is elevated (Fahrenberg, Franck, Baas, & Jost, 1995).









However, some clinicians and researchers report that certain patients are able to detect

when their BP is elevated (Barr, Pennebaker, Watson, 1988). These patients often report

vague symptoms that are associated with their high BP. Symptoms such as headache,

racing heart, sweaty hands, cold/warm hands, tight stomach, muscular tension, dizziness,

blurred vision, lightheadedness, tension, palpitations, flushed face, and warm/cold

extremities have been correlated with variations in BP (Bulpitt, Dollerly, & Came, 1976;

Pennebaker, Gonder-Frederick, Stewart, Elfman, & Skelton, 1982).

There are many hypotheses behind the development and maintenance of

hypertension. These theories provide a framework for understanding how patients with

high BP can be helped to recognize the subtle signs and symptoms. One hypothesis of

hypertension development is the sympathetic nervous system theory of hypertension

development. This hypothesis describes hypertension as a result of over-stimulation of

the SNS. To substantiate SNS overactivation, several studies of patients with essential

hypertension demonstrate increased levels of plasma norepinephrine and elevated

norepinephrine spillover. Patients with borderline and essential hypertension have an

increased sympathetic and a decreased parasympathetic drive (Rahn, Barenbrock, &

Hausberg, 1999). It is hypothesized, and highly debated, whether sympathetic nervous

system (SNS) activation is a trigger for high BP (defense reaction) or if SNS activation is

due to a secondary phenomenon (e.g., endothelial or baroreceptor dysfunction).

Alterations and/or uncompensated increases in SNS activity in hypertensives may cause

subtle physical signs and symptoms. Increased SNS activity and early hypertension are

often characterized by an increased heart rate, cardiac output, and renal vascular

resistance. The sympathetic nervous system elicits a "fight or flight" response when

confronted with a stimulus, such as when the person is in an emergency or stressful









situation. Additionally, symptoms that are related to increased SNS activity have been

reported in hypertensives and have been correlated with high BP episodes (Carels,

Sherwood, & Blumenthal, 1998).

Potential manifestations of increased SNS activity include increased heart rate

and stroke volume (cardiac output), increased cardiac contractility and venous return,

renal retention of sodium and water, increased thirst, increased venous tone, increased

angiotensin II, increased peripheral resistance, increased local vasoconstrictors/regulators

(e.g., endothelin), increased blood viscosity, and decreased local vasodilators/regulators

(e.g., nitric oxide). Symptoms associated with high BP may be related to overstimulation

or oversensitivity of the SNS in hypertensive individuals (Esler, 2000; Kaplan, 1998;

Rahn, Barenbrock, & Hausberg, 1999).

It has been reported that individuals, both normotensive and hypertensive,

estimate their BP levels by using both internal sensory and external situational

information (Barr et al., 1988). Estimations and beliefs about BP levels may or may not

be accurate, but they are important because people act upon them. In fact, Pennebaker et

al. (1982) suggest that variations in BP are correlated to different symptoms and that a

person can monitor his or her BP by monitoring symptoms. Interestingly, in studies

where both normotensive and hypertensive people were asked to estimate their BP levels,

estimated BP was strongly associated with symptoms and moods (Baumann & Leventhal,

1985) and with feelings of physical tenseness and physical activity (Fahrenberg et al.,

1995).

Several studies on whether or not people can accurately estimate their BP have

been performed. The findings have been fraught with much speculation and conflicting

results (Barr et al., 1988; Baumann & Leventhal, 1985; Brondolo, Rosen, Kostis, &









Schwartz, 1999; Cinciripini, Epstein, & Martin, 1979; Fahrenberg et al., 1995;

Greenstadt, Shapiro, & Whitehead, 1986; Luborsky et al., 1976; Shapiro, Tursky, &

Schwartz, 1970). An important variable among these studies was the addition of a

feedback intervention. Among the feedback intervention-type studies, all showed an

improvement in BP discrimination after feedback (Barr et al., 1988; Brondolo et al.,

1999; Cinciripini et al., 1979; Greenstadt et al., 1986; Luborsky et al., 1976; Shapiro et

al., 1970).

Different types of feedback have been used to assist subjects in learning to

recognize symptoms, situations, and factors that are associated with their BP levels.

Barr, Pennebaker, and Watson (1988) provided normotensive subjects actual

biosituational factors (e.g., symptoms, moods, situations) that were related to their SBP

levels. They found that 71.4% of the subjects in the biosituational feedback group had

significant accuracy correlations compared with 31.3% of the subjects in the control (no

feedback) group. Additionally, providing normotensive (Barr et al., 1988; Cinciripini et

al., 1979; Greenstadt et al., 1986) and hypertensive subjects' (Brondolo et al., 1999

Luborsky et al., 1976; ) knowledge of their actual BP levels has also been used to

improve accuracy in estimating BP levels.

Problem Statement

Because of the continued prevalence and incidence of hypertension and its

complications, there must be more research focused on testing detection and intervention

strategies, as well as improving patient compliance (AHA, 2003c; Miller, Hill, Kottke, &

Ockene, 1997). The American Heart Association Expert Panel on Compliance (Miller et

al., 1997) reported that a multilevel approach featuring both behavioral and educational









strategies was needed to assist patients and providers in improving compliance (Miller,

Hill, Kottke, & Ockene, 1997).

Because the majority of BP feedback intervention-type studies have been

performed on normotensive, healthy volunteers, it is unknown whether adults with

hypertension can accurately estimate their BP or if this awareness can be improved

through BP or biosituational feedback. Specifically, it is unknown if hypertensive adults

can estimate their SBP more accurately after participating in ambulatory BP feedback

and biosituational self awareness training.

Purposes of the Study

The purposes of the study are as follows:

1. To determine if there are differences in the mean absolute difference (AD)
among adult hypertensives after training compared to before training.

2. To determine if there are differences in the mean improvement of
estimating SBP among college-educated hypertensives versus noncollege-
educated hypertensives.
3. To determine if college-educated hypertensives decrease their mean AD
posttraining compared to pretraining.

4. To determine if there are differences in the mean improvement of
estimating SBP between hypertensives whose body mass index (BMI) is >
30 and hypertensives whose BMI is < 30.

5. To determine if there are differences in the mean improvement of
estimating SBP between male hypertensives and female hypertensives.

6. To determine if there are differences in the mean improvement of
estimating SBP between hypertensives who are < 48 years of age
compared with those who are > 48 years of age.

7. To determine if there are differences in the mean improvement of
estimating SBP between hypertensives who use antihypertensive
medications and those who do not use antihypertensive medications.









Hypotheses

The hypotheses investigated are listed below:

1. Adult hypertensives differ significantly in their mean improvement of
estimating SBP after the ambulatory BP awareness training intervention,
compared with before the training intervention.

2. College-educated hypertensives differ significantly from noncollege-
educated hypertensives in their mean improvement of estimating SBP.

3. College-educated hypertensives decrease their mean AD posttraining
compared to pretraining.

4. Hypertensives with a BMI < 30 differ significantly from hypertensives
with a BMI > 30 in their mean improvement of estimating SBP.

5. Male hypertensives differ significantly in their mean improvement of
estimating their SBP compared to female hypertensives.

6. Hypertensives < 48 years of age differ significantly in their improvement
of estimating SBP compared to hypertensives > 48 years and older.

7. Hypertensives using antihypertension medication differ significantly in
their mean improvement of estimating SBP compared with hypertensives
not taking medications.

Definitions of Terms

The absolute difference (AD) is defined as the absolute value of the mean

difference between actual and estimated SBP. The absolute difference was calculated for

mean actual SBP days 1, 2 and 3, and 4 and mean estimated SBP days 1, 2 and 3, and 4.

Actual SBP is defined as that which is measured using the ambulatory BP

monitor; it is viewed as a continuous variable with parameters defined as mean, standard

deviation, and variance.

Ambulatory BP feedback is defined as those BP readings from the ambulatory BP

monitor that can be viewed by the patient on the unblinded LCD screen.









Ambulatory BP monitoring is defined as an automatic, noninvasive cuff-

oscillimetric recorder (Model 90207, SpaceLabs, Inc., Redmond, WA) which measures

ambulatory BP. Subjects wear the ambulatory BP monitor cuff in a similar fashion as a

standard manual sphygmomanometer. However, the ABP monitor is preprogrammed via

specialized software to automatically measure BP at preset intervals throughout the day

and night. The subject wears the cuff around his/her upper forearm and the main unit is

strapped around the waist via a strap or belt. ABP monitoring is a reliable and

naturalistic method for obtaining BP readings while subjects are in their normal

environment.

Biosituational feedback is defined as feedback related to biological, situational,

psychological factors that the subject has experienced. Biosituational feedback in this

study is provided to the subject by providing the subject with information on their actual

SBP, self-reports of their estimated SBP, and self-reports of their moods, symptoms, and

activities during BP measurement.

A blinded-LCD screen is the panel on the ABP monitor that displays the time of

day, but does not display the physiologic data (i.e., the patient cannot view the BP

measurement).

Estimated SBP is defined as that which is estimated by each subject; it is viewed

as a continuous variable.

Hypertension is defined as SBP of 140 mmHg or greater, diastolic BP of 90

mmHg or greater, and/or taking antihypertensive medication.

Hypertensive subjects are identified as hypertensive if they have BP readings

greater than 140/90 on both of the two screening BP measurements or they are taking

antihypertensive medications.







11

The mean improvement is defined as the absolute value of the mean difference of

day 1 (mean actual SBP minus mean estimated SBP) minus the absolute value of the

mean difference of day 4 (mean difference of actual SBP minus estimated SBP).

An unblinded-LCD screen is the panel on the ABP monitor that displays the time

of day and allows the subject to view the SBP, DBP, and heart rate.

Assumptions

The following assumptions were made in this study:

1. Participants have some knowledge of their health status, including BP and ways
to treat high BP.

2. Participants have some opinions about their BP patterns and factors relating to
their high BP.

3. Participants have access to various sources of information about high BP.

4. Participants may have symptoms and patterns that are associated with their high
BP.

5. People with high BP may have alterations in autonomic nervous system
functioning that may predispose them to have symptoms during high BP episodes.

6. Symptoms, patterns, and causes of high BP vary from person to person.

7. Patients with hypertension have variability in their SBP of at least 30-50 mmHg
in a 24-hour period.

Limitations

The generalizability of the results of this study is limited to adult hypertensive

persons who live in the North Central Florida area. Despite this limited geographic

range, the population is believed to be similar to the population of hypertensive persons

in other parts of the United States.

Significance of the Study

Hypertension is a major cause of death in the U.S. and worldwide. Only about

one quarter of adults with hypertension are being adequately controlled on medications









(AHA, 2003c). Because of this, there will be increased economic burden and increased

morbidity and mortality associated with high BP. Hypertension is difficult to treat for a

variety of reasons. One issue is that hypertension is a relatively asymptomatic disorder

and patients may not even realize that their BP is elevated. Because there has been

limited research inquiry into hypertensives' awareness of their BP levels, it is generally

unknown whether hypertensives can improve their ability to estimate their BP. Research

has indicated that SBP is an important determinant to the risk of coronary heart disease,

stroke, and end-stage renal disease (He & Whelton, 1999). Because of the importance of

SBP prediction and modification, this study examined the ability of adult hypertensive

persons to estimate their SBP before and after a biosituational feedback training

intervention. A better understanding of estimation of SBP among hypertensives will

encourage researchers to study and develop new and better-tailored treatment modalities.

This study also utilized ABP monitoring and a self-report diary to assist adults with

hypertension to learn more about their BP patterns and associated factors. Finally, this

study examined differences between different groups of hypertensives. This information

will shed light on potential sub-groups that may be better or worse at estimating their

SBP and may encourage a more focused inquiry into SBP estimation and biosituational

feedback training. Additionally, if hypertensives can improve their ability to estimate

their SBP levels, there may be improved adherence to medications, improved

hypertension therapies, and improved outcomes.















CHAPTER 2
REVIEW OF LITERATURE

This chapter will present a literature review of the following areas of research:

theories of hypertension development, systolic hypertension, role of sympathetic nervous

system in hypertension, issues surrounding the treatment of hypertension, biosituational

factors associated with high BP, BP estimation, and ambulatory BP monitoring. A

summary linking these areas together to provide a research rationale for this study will

conclude this chapter.

Theories of Hypertension Development

There have been several mechanisms that have been implicated in hypertension

development. These mechanisms include impaired baroreceptor function, increased

sympathetic nervous system activity, impaired endothelial function, and/or structural-

adaptive changes in the vascular walls.

Impaired Baroreceptor Function and Baroreceptor Resetting

The baroreceptor mechanism in the central nervous system assists with the

regulation and control of arterial pressure. Baroreceptors are nerve endings that lie in the

walls of large arteries and are stimulated when stretched. This reflex is initiated by

pressure-sensitive receptors, located in the walls of the large arteries of the neck and

thoracic regions, carotid artery, and the aortic arch. The baroreceptors respond rapidly to

acute drops or elevations in BP. The baroreceptor signal is transmitted, enters the

medulla, and stimulates either the sympathetic nervous system (SNS) (if BP is too low)







14

or the parasympathetic nervous system (PNS) (ifBP is too high). Stimulation of the SNS

promotes the secretion of both norepinephrine (NE) and epinephrine and causes

vasoconstriction in vascular smooth muscles and blood vessels and increased strength of

heart contraction. Stimulation of the PNS would promote the secretion of acetylcholine

and cause vasodilation of the veins and arterioles and decreased heart rate and strength of

contraction. The baroreceptor mechanism is an extremely powerful and effective entity

within the nervous and cardiovascular systems for short-term regulation of BP

(Chapleau, Cunningham, Sullivan, Watchel, & Abboud, 1995; Harrington, Murray, &

Ford, 2000; Seeley, Stephens, & Tate, 1998).

One of the problems with the baroreceptor system in the long-term regulation of

arterial pressure is that the baroreceptors are continually "reset" after 1 to 2 days of

prolonged pressure exposure. Consequently, they are only effective if the change in BP

is acute or not prolonged. For example, if the pressure rises from the normal 100 mmHg

to 170 mmHg, there would be an acute and immediate response from the baroreceptor

reflex (vasodilation). The rate of impulse firing is rapid and extremely acute, and then

diminishes over the course of a few seconds. The rate of impulse firing continues to

decline over a period of 1 to 2 days until ultimately the rate of firing ceases, despite the

fact that the arterial pressure remains at 170 mmHg. Thus, the baroreceptor has been

"reset" to be accustomed to a consistently high BP level (Chapleau et al., 1995; Guyton

& Hall, 1996).

It is interesting to note that studies have shown that young, mild or borderline

hypertensive patients have an increase in BP variability and skeletal muscle sympathetic

nerve activity, and display increased baroreceptor activity. This may be a compensatory

finding that is associated with increased sympathetic nerve activity, whereby the







15

baroreceptors are attempting to adjust the BP toward more normal levels. In established

hypertension associated with myocardial hypertrophy and decreased myocardial stretch-

ability, baroreceptor function has been shown to decline (Chapleau et al., 1995).

The baroreceptor reflex may also not be effective in long-term regulation of BP

because of the structural and functional changes that are seen in the blood vessels of

patients with hypertension. Because of the anatomical location of the baroreceptor nerve

endings, dysfunction of the vessel lumen/endothelium may decrease the baroreceptor

pressure-sensor effectiveness (Chapleau et al., 1995; Seeley et al., 1998).

Another problem of short- and long-term baroreceptor regulation of arterial BP is

that even under conditions of "normal" aging, baroreceptor function and other

cardiopulmonary neural regulatory functions have been shown to be less effective with

age. In animal studies, the effects of administration of acetylcholine on heart rate

(i.e., bradycardia) are more pronounced in elderly normotensive subjects than in younger

controls. The baroreceptor control of BP in normal subjects is reported to be comparable

to that of the younger controls; however, the response to the stimulus (either high or low

BP) is sluggish and slower. Thus, baroreceptor control of BP becomes impaired with the

aging process, however to a lesser degree than heart rate regulation. Studies have also

shown that there is impairment in the cardiogenic stretch receptors located in the

cardiopulmonary region that are associated with aging (Chapleau et al., 1995; Fauvel et

al., 2000; Giannattasio et al., 1994). Impaired baroreceptor function and baroreceptor re-

setting may lead to uncompensated increases or decreases in BP. It remains unclear

whether baroreceptor dysfunction is the cause or effect of hypertension.









Sympathetic Hyperactivity Theory

In the sympathetic hyperactivity theory of hypertension, hypertension is caused

by an abnormally increased stimulation of the sympathetic nervous system. Increases in

catecholamine stimulation effect BP by increasing heart rate, stroke volume, and

peripheral resistance. Factors that may be associated with increased sympathetic outflow

and increased total peripheral vascular resistance in essential hypertension include

baroreflex re-setting; genetic composition; stress; altered renin-angiotensin-aldosterone

mechanisms; alterations in circulating hormones/substances; structural-adaptive changes

in vascular walls; endothelial dysfunction; endothelial derived relaxing and contracting

factors; and membrane and intracellular mechanisms, including impaired adrenergic

receptor numbers and types. The increase in SNS activity stimulates the release of

catecholamines to effect specific target organs including the vascular smooth muscle,

blood vessels, kidneys, and heart. Effects of increased SNS activity include increased

heart rate and stroke volume (cardiac output), increased cardiac contractility and venous

return, renal retention of sodium and water, increased thirst, increased venous tone,

increased angiotensin II, increased peripheral resistance, increased local

vasoconstrictors/regulators (i.e., endothelin), increased blood viscosity, and decreased

local vasodilators/regulators (i.e., nitric oxide) (Lilly, 1998).

Folkow (1982) proposed a "defense-reaction" theory of increased sympathetic

activity in hypertension. Folkow hypothesized that certain individuals may undergo

defense reactions to conditioned stimuli on a daily basis; without the actual fight-or-flight

reaction, and this would in-turn cause marked increases in sympathetic activity. If the

conditioned stimuli were continually repeated, adverse structural adaptive changes of the

arterioles would occur, thus leading to the further development of sustained hypertension









(Brondolo, Karlin, Alexander, Borrow, & Schwartz, 1999; Carels et al., 1998; Folkow,

2000; Wright & Angus, 1999).

In numerous studies of young patients with essential hypertension, it has been

shown that there are increased levels of plasma norepinephrine and elevated

norepinephrine spillover (Esler, 2000; Grassi et al., 2000; Rahn et al., 1999). In a study

by Egan, Panis, Hinderliter, Schork, & Julius (1987), mildly hypertensive young humans

had elevated plasma norepinephrine levels and enhanced skeletal muscle vasoconstrictor

tone. These findings provide understanding of the hemodynamic profile of early human

hypertension, which is characterized by increased heart rate, cardiac output, and renal

vascular resistance. Increased sympathetic activity has also been shown to be a factor in

elderly hypertension. In a study by Grassi et al., (2000), muscle sympathetic nerve

activity was increased in 20 untreated elderly essential hypertension patients compared

with age-matched controls. In addition to subjects with existing hypertension,

normotensives with a family history of hypertension have higher rates of norepinephrine

spillover into arterial plasma than do normotensives without a family history of

hypertension. This finding may be a contributing factor and provide a link for the later

development of hypertension. It was also reported that patients with accelerated essential

hypertension have significantly higher levels of muscle sympathetic nerve activity than

do patients with milder hypertension. There have been several proposed mechanisms for

increases in muscle sympathetic nerve activity in essential hypertension. One such

proposal is that increases in muscle sympathetic nerve activity may be related to

increased central nervous system sympathetic outflow. Another such hypothesis is that

patients with essential hypertension have impaired baroreflex sensitivity (Mark, 1996).









Increased sympathetic activity and enhanced reactivity to stress have been

reported in patients with both borderline and established hypertension, and it has been

suggested that they play a role in the pathogenesis of hypertension. The mechanism for

these enhanced responses is unknown; however, it has been suggested that epinephrine,

released from the adrenal medulla during physiological stress, is taken up into the

sympathetic nerve terminal and later released as a co-transmitter with norepinephrine.

The norepinephrine that has been released further stimulates norepinephrine release

through its action on the presynaptic B-adrenergic receptors. In a recent study,

hypertensive subjects had a 25% higher rate of whole body spillover of norepinephrine to

plasma, compared to normotensive controls. Additionally, the epinephrine secretion rate

was increased in hypertensives (215 +/- 209ng/min) versus normotensives (173 +/- 115

ng/min). These findings provide evidence the epinephrine may prolong and amplify the

sympathetic responses at a time when circulating ephinephrine concentrations are no

longer elevated (Rumantir et al., 2000; Stein, Nelson, He, Wood, & Wood, 1997).

There have also been studies that demonstrate differences in SNS activity among

subsets of the population. Stein, Lang, Singh, He, and Wood (2000) reported that

healthy, normotensive black males (compared to age-matched white males) had

markedly increased levels of vascular sensitivity to an infusion of the alpha-adrenergic

vasoconstrictor substance, phenylephrine (Stein et al., 2000). This study concluded that

increased sympathethetically-mediated vascular tone caused by enhanced

vasoconstriction and attenuated vasodilation may play a role in the pathogenesis of

hypertension in blacks. It has also been reported that obese-normotensive and obese-

hypertensive subjects have impaired adrenergic and baroreflex function. In a recent

study, Grassi et al. (2000) reported that muscle sympathetic nerve activity is significantly









increased in lean hypertensive and overweight normotensive subjects (p = 0.01),

compared to lean normotensive control subjects. Additionally, obese-normotensive and

obese-hypertensive subjects had impaired baroreflex cardiovascular control, as measured

by the infusion ofvasoactive drugs (nitroprusside and phenylephrine) and the response of

each substance. This study concluded that the association between obesity and

hypertension triggers a sympathetic activation and an impairment in baroreflex control

mechanisms (Grassi et al., 2000; Julius, Valentini, & Palatini, 2000).

Endothelial Dysfunction

The endothelium is closest to the arterial lumen, in the intimal layer, and intimate

with blood flow. In the normal artery, the endothelium functions to maintain the

integrity of the vessel wall by performing various metabolic and signaling functions. The

endothelium functions to (a) act as a barrier and protect subendothelial space, (b) express

antithrombogenic substances (heparin, thrombomodulin, plasminogen activitators), (c)

secrete vasoactive substances that promote vasodilation (endothelium-derived relaxing-

factor and prostacyclin), and (d) inhibit smooth muscle cell migration and proliferation

by secretion of heparin and endothelium-derived relaxing factor. Atherosclerotic lesions

develop within the intimal layer (Lilly, 1998; Luscher, 1994).

Over the last several years, increasing attention has been paid to a substance

secreted by the endothelium known as Endothelium-derived-relaxing-factor (EDRF), also

known as Nitric Oxide (NO). In addition to its vasodilatory properties, NO is known to

inhibit platelet aggregation and adhesion, monocyte adherence and chemotaxis, and

proliferation of vascular smooth muscle cells. Endothelium-derived nitric oxide, a potent

vasodilator, may be an endogenous antiatherogenic factor. In animal and human models,

vasodilation caused by the release of endothelium-derived NO is diminished in









atherosclerotic vessels. In addition, hypercholesterolemia independent of observable

atherosclerosis inhibits endothelium-dependent vasodilation. In addition to NO, the

endothelium also produces potent vasoconstrictor substances including endothelin-1.

The expression of endothelin-1 is stimulated by factors including thrombin, angiotensin-

II, epinephrine, and the shear stress of blood flow (Chowdhary et al., 2000; Lilly, 1998;

Luscher, 1994).

Because of the protective nature of the endothelium, it is important that the

integrity of the endothelium be intact. In response to some type of "injury" to the

endothelial layer, the endothelium undergoes a continuum of changes that adversely

affect the structural and functional physiology of the endothelial surface. Injured

endothelium demonstrates increased permeability to large molecules and substances

under the subendothelial space, reduced antithrombotic properties and increased

vasoconstriction due to decreased secretion of prostacyclin and EDRF-NO, and increased

smooth muscle cell migration and proliferation due to decreased secretion of EDRF-NO

and platelet-derived growth factor (PDGF). Atherosclerosis is a disease of the muscular

arteries (e.g., aorta, coronary and cerebral vessels) in which the intimal layer becomes

"injured" and thickened by fatty deposits and fibrous tissue. Elevated levels of serum

cholesterol aggravate the vessel endothelium integrity and cause changes within the

vessel lumen. The earliest visible lesion of atherosclerosis is a fatty streak characterized

microscopically by the subendothelial accumulation of large, lipid-laden "foam cells."

Foam cells are derived from macrophages and smooth muscle cells (SMC's). Factors

involved in monocyte migration and accumulation in the subendothelial space include

increased levels of serum cholesterol, especially low-density lipoproteins (LDLs) and

oxidized LDLs which encourage the presence of adhesion molecules and chemotactic









proteins. Once in the subendothelial space, the monocytes become activated

macrophages and release mitogens and chemoattractants (including tumor necrosis

factor, interleukins, complement fragments, PDGF, immune complexes, smooth muscle

cell growth factors, and monocyte chemo-attractant proteins) that recruit additional

monocytes and promote SMC growth and clot promotion. In advanced disease, a fibrous

plaque of SMC origin develops in the intimal layer when there is continual accumulation

of monocytes, lymphocytes, foam cells, and connective tissue. Complications occur due

to weakening of the vessel wall, ulceration of the vessel wall, occlusion of vessel lumen,

thrombosis and distal embolization (Chalmers, 2000; Lilly, 1998; Luscher, 1994;

Schwartz, Reidy, & De Blois, 1996).

Hypertension probably is a risk factor of endothelial dysfunction, as increases in

sympathetic nervous system activity have been shown to injure vascular endothelium and

may increase the permeability of the vessel wall to lipoproteins and other atherogenic

factors (Lilly, 1998; Toikka et al., 2000). Because endothelin-1 is stimulated by

mechanisms that are affected by increased SNS activity and a majority of patients with

hypertension have clinically increased SNS activity, it could be possible that these

factors may influence peripheral resistance, and therefore BP. In addition, decreases in

endothelium-derived vasodilating and increases in endothelium-derived constricting

factors cause an increase in BP and vascular resistance and this may be a risk factor for

hypertension development. In a recent study by Park, Charbonneau, and Schiffrin

(2001), endothelial dilatory responses to acetylcholine infusion in the brachial artery

correlates with the presence of endothelial dysfunction in human resistance arteries. In

this study, endothelial-dependent dilatory responses were found to be similar in large and

small arteries in hypertensive patients. This conclusion suggests that endothelial









dysfunction may have a systemic rather than a local nature in atherosclerosis and

hypertension (John & Schmieder, 2000; Park et al., 2001).

Endothelial dysfunction, atherosclerosis, and/or hyperlipidemia may also

precipitate alterations in the integrity of the protective endothelium and thereby increase

vasoconstrictor substances, leading to hypertension. Hypothetically, if a person had early

atherogenesis and/or hypercholesterolemia but no hypertension, he/she may have

impaired EDRF-NO function and increased endothelin-1 stimulation and therefore may

have increases in systemic BP (Lilly, 1998; Park et al., 2001).

Baroreceptor function may be modulated by factors such as prostacyclin, oxygen-

free radicals, and factors released from aggregating platelets (Chapleau et al., 1995).

Endothelial dysfunction and subsequent altered release of these factors contribute

significantly to the decreased baroreceptor sensitivity in hypertension and

atherosclerosis. Dysfunctional changes in the endothelium may impair baroreceptor

function by reducing the stretch mechanisms that provide signals to the autonomic

nervous system. Chapleau et al. (1995) reported that the inhibition of endogenous

formation of prostacyclin and increased platelet aggregation reduced baroreceptor

activity in healthy rabbits. Additionally, oxygen free-radical generation (as seen in

atherosclerotic lesions and oxidized-LDL) suppressed baroreceptor activity in the normal

carotid sinus (Chapleau et al., 1995).

Structural/Functional Theory

As mentioned previously, various structural and functional changes occur within

the vessel wall that may encourage the development and maintenance of hypertension.

Structural and adaptive changes that occur in the vessel wall and cardiovascular system

include vascular and left ventricular hypertrophy, arterial stiffness, decreased vessel









compliance, and atherosclerosis of the coronary and carotid arteries. In a study

comparing age-matched borderline versus normotensive subjects, increased carotid and

brachial intima-media thickness was seen in the borderline hypertensive group. In

addition, oxidized-LDL was increased in the borderline hypertension group compared

with the control group (Toikka et al., 2000). Interestingly, a study of moderately

hypercholesterolemic and hypertensive subjects reported that systolic BP and pulse

pressures are associated with alterations in increased carotid-intimal thickening

(Zanchetti et al., 2001).

Structural and functional changes that occur in the pathophysiological processes

of atherosclerosis, SNS overactivation, and endothelial dysfunction can impair baroreflex

function (Chapleau et al., 1995), impede blood flow, increase resistance of flow, increase

BP, and can encourage a number of advanced adverse complications of hypertension

including thrombosis formation, stroke, myocardial infarction, renal failure, retinopathy,

and death. It is interesting to note, however, that human vessels can undergo massive

accumulations of atherosclerotic plaque without narrowing of the lumen. This may be

due to compensatory remodeling of the vessel wall and dilating to permit a normal level

of blood flow. In studies of balloon-injured rabbit carotid arteries, researchers found no

narrowing of the vessel lumen despite an increase in wall thickness (Schwartz et al.,

1996). Increased sympathetic adrenergic activity can also increase arterial stiffness and

decrease vessel compliance. Increased workload on the heart induced by hypertension

and/or SNS activity causes hypertrophy of the left ventricle and decreased compliance of

the ventricle to properly fill and contract blood. The level of arterial pressure exerts an

important influence on the level of left ventricular muscle mass. Approximately 20% to









35% of variability in LV mass can be predicted from the level of 24-hour ambulatory

BPs (Devereux, de Simone, Ganau, & Roman, 1994).

In summary, it is clear that there are many factors that are related to hypertension

development and maintenance. Hypertension development and maintenance is most

likely extremely individual and probably a function of a combination of the discussed

mechanisms and alterations. Because of the complex nature of the vasculature,

circulatory, and neurological systems, each of these theories impacts SNS activity and

thereby could promote hypertension development and maintenance.

For the purposes of this study, the SNS hyperactivity theory of hypertension

development will be explored as a possible link between high BP and high BP

recognition. In the SNS hyperactivity theory of hypertension, high BP is caused by an

abnormally increased stimulation of the SNS. The exact mechanism for increased SNS

activity in hypertension is largely unknown, but has been speculated by researchers

(Folkow, 1982). As mentioned previously, the increase in SNS activity stimulates the

release of catecholamines to affect specific target organs including the vascular smooth

muscle, blood vessels, kidneys, and heart. Stimulation of the SNS causes physiological

manifestations, such as racing heart, pounding chest, increased BP, and dilated pupils.

Studies show that there are increased levels of plasma norepinephrine and

elevated norepinephrine spillover in essential and borderline hypertension, seen in both

younger and older hypertensives (Egan et al., 1987; Esler, 2000; Grassi et al., 2000; Rahn

et al., 1999;). Because age has been shown to be a factor in increased SNS activity, it

would seem plausible that adults of increased age or younger borderline hypetensives

would have increased SNS output and therefore potentially more manifestations of SNS

activity. Similarly, adults who are obese have been shown to have impaired adrenergic







25

and baroreflex function (Grassi et al., 2000). Therefore, obese adults may have physical

signs or symptoms associated with BP elevation. Whether or not this activity occurs

only during a high BP episode or if it occurs more consistently is unknown. It is also

unknown whether obese or elderly hypertensives have an increased recognition or

awareness of high BP or high levels of sympathetic activity.

Systolic Hypertension

The majority of persons with systolic hypertension are not adequately controlling

their BP levels despite persuasive data from clinical trials documenting the benefit of

treatment (JNC VI, 1997, p. 6). Systolic BP has been identified as a major measure in

the assessment of risk in hypertensive subjects (Lackland, 1999). Observational

epidemiologic studies and randomized controlled trials have demonstrated that SBP is an

independent and strong predictor of risk of cardiovascular and renal disease (Franklin et

al., 2001; He & Whelton, 1999). Recent data from the Systolic Hypertension in the

Elderly Program (SHEP) have indicated a clear benefit of treatment with a reduction in

total stroke of 36%, and a reduction of 25% and 32% in the combined end points of

coronary heart disease and cardiovascular disease, respectively (Silagy & McNeil, 1992).

SBP levels have been shown to covary more with physical symptoms than either

DBP or heart rate (Pennebaker et al., 1982). From a perspective of training patients to

recognize high BP episodes, it has been shown that discrimination of systolic pressures

occurs at a slightly faster pace than diastolic pressures (Cinciripini et al., 1979). It also

may be easier for subjects to understand the estimation task as well as minimize

confusion between SBP and DBP levels, thereby increasing the reliability of the SBP

estimate. Because of the importance of SBP as a predictor in long-term outcomes and







26

the ease of conceptualization, it is valuable to solely examine the ability of hypertensive

persons to estimate their SBP levels.

Issues Surrounding the Treatment of Hypertension

Overview of Treatment Statistics in High BP

A goal of therapy for patients with hypertension as defined by the JNC VI report

(1997) is to reduce BP to nonhypertensive levels with minimal to no side effects.

According to recent estimates from the American Heart Association (AHA), one in four

U.S. adults has high BP, but because there are no symptoms, nearly one-third of these

people don't even know they have it. The current goal for BP is to have BP controlled to

less than 140/90 mm Hg. However, it is estimated that only 26.2% of people with high

BP are on antihypertensive medications but do not have it under control. For a historical

perspective, in 1972, 16% of high BP patients were controlled to less than 160/95 mm

Hg, the goal at the time. A recent AHA survey indicated that the control rate for today's

goal of less than 140/90 mm Hg is 29% (AHA, 2003a). Thus, it would seem that we are

making progress, but we have a long way to go. The economic burden of uncontrolled

hypertension is immense. For example, researchers estimated the number of cases and

costs of myocardial infarction, stroke, and congestive heart failure for patients achieving

BP control versus those not achieving control. For the U.S. population with hypertension,

inadequate BP control was estimated to result in 39,702 cardiovascular events, 8,374

cardiovascular disease deaths, and $964 million in direct medical expenditures. Within

the medicated population with cardiovascular disease, the incremental costs of failure to

attain BP goals reached approximately $467 million. These results reflect the importance

of adequate BP control, in particular, systolic BP control, in reducing cardiovascular









morbidity, mortality, and overall health care expenditures among patients with

hypertension (Flack et al., 2002).

Poor adherence to antihypertensive therapy is a major therapeutic challenge

contributing to the lack of adequate control in more than two-thirds of patients with

hypertension (Miller et al., 1997; JNC VI, 1997). Compliance is often defined as

implementation (by the patient) of the therapeutic plan that has been established

(Anderson et al., 1994). Nearly three-fourths of adults with hypertension are not

controlling their BP to below the recommended 140/90 mmHg (JNC VI, 1997).

Noncompliance is a multi-faceted biobehavioral issue that may be related to factors such

as economics, past history, perception of illness threat, effect illness has on daily

activities or work, presence of symptoms associated with the illness, and perception of

efficacy of therapy. Patients with chronic illnesses, especially hypertension that presents

few recognizable symptoms if any, often have difficulty prescribing meaning to their

illness. Therefore, these patients have problems complying with their therapeutic plans

(Meyer et al., 1985; McLane et al., 1995). If patients with hypertension can learn to

recognize symptoms or factors that are associated with their high BP and learn to

recognize when their BP is high, their compliance with prescribed therapy and

motivation to seek or continue treatment may improve.

At the same time that hypertensives are having problems with adhering to

treatment regimens, people throughout the world are beginning to embrace an emerging

trend called "self-managed care." Self-managed care is a term used to describe the act

ofmaintaining one's own health and well-being (Strohecker, 1999). Individuals today are

looking to manage their own health by becoming empowered and being vigilant

healthcare consumers. Because of the recommendation by the Healthy People 2010









campaign to improve patients' awareness of their BP levels and to improve the

percentage of people who know if their BP level is low, normal, or high, it is clear that it

would be beneficial for patients to have increased knowledge of their BP levels and

factors associated with their high BP. With this in mind, it makes sense that the major

health care organizations and programs are encouraging patients to have increased

awareness of BP levels and to use automatic home BP monitors to assist in the

management of hypertension (AHA, 2003a; Healthy People 2010, 2003; JNC VI, 1997).

Educational level has an impact on health and health outcomes, as educated people have

been shown to be healthier and have more improved outcomes to treatments, whereas

people of lower socioeconomic status tend to have more adverse risk factors and worse

health (Winkleby, Fortmann, & Barrett, 1990). It seems reasonable that if patients were

more aware of their high BP episodes and factors associated with them, they would be

more motivated to seek and/or continue treatment (Meyer et al., 1985; McLane et al.,

1995). Additionally, learning to recognize high BP may provide a means to teach patients

to use relaxation, biofeedback, and/or pharmacologic therapies as a means of reducing

elevated BP levels, thereby improving treatment outcomes.

Antihypertensive Medications

Medications, known as "antihypertensive medications," are available to treat

chronic high BP. There are various types and classes of antihypertensive medications.

Each type of medication works at a different site of action in the body to lower BP. Each

medication has potential side effects that may occur with use of the medication. Often,

antihypertensives are used alone or in conjunction with other antihypertensive

medications. Because of the complex nature of hypertension, often two or more drugs or

therapies are needed to control BP to a normal level. The JNC VI report on Prevention,







29

Detection, Evaluation and Treatment of High BP recommends that a diuretic and/or beta

blocker be chosen as initial therapy for hypertension, unless there are specific

contraindications or reasons to choose otherwise (JNC VI, 1997).

Diuretics are a type of medication used to treat hypertension and a variety of

other illnesses that work by acting to increase urine output, thereby decreasing BP.

Diuretics inhibit sodium reabsorption and affect electrolyte excretion in a particular

nephron segment. Different classes of diuretics are available and they are generally

classified based on their major site of action within the nephron. Depending on the

diuretic class, major sites of action include the proximal tubule, thick ascending limb of

the loop of Henle, early distal tubule, and late distal and early collecting tubule. Classes

of diuretics include proximal tubule diuretics (Acetazolamide), loop diuretics

(Furosemide), thiazide diuretics (Hydrochlorothiazide), potassium-sparing diuretics

(Spironolatctone), and osmotic diuretics. Diuretics are generally well tolerated and side

effects are minimal; however, care should be taken to avoid electrolyte imbalances.

Diuretics are frequently used alone or in combination with other antihypertensive

medications for the treatment of hypertension (Smith & Reynard, 1995).

Calcium channel blockers (CCBs) are another type of medication that are used to

treat hypertension. CCBs block the movement of calcium into the arteriolar smooth

muscle and cardiac cells and may inhibit the mobilization of calcium within these cells.

In the treatment of hypertension, CCBs act as arteriolar dilators and reduce systemic

vascular resistance. CCBs are effective as monotherapy and in conjunction with other

antihypertensive medications, especially beta-blockers and central sympatholytics (Smith

& Reynard, 1995).









Beta blockers (BB) are also very effective in lowering BP in hypertension. BBs

are competitive antagonists for norepinephrine and epinephrine receptor sites in the heart,

bronchioles, and blood vessels in the skeletal muscles. The mechanism of BB action is

accomplished by blocking the beta receptors in the heart, bronchioles, and blood vessels

in skeletal muscle, and promoting vasodilation and decreasing BP. BBs decrease cardiac

output, central sympathetic output, presynaptic beta receptor inhibition, and inhibition of

renin. Different types of BBs are classified according to their site of action and

selectivity of beta receptor sites. Beta-1 selective acting agents are selective for beta

receptor sites in the heart. For example, two agents that are relatively cardio-selective

include Metoprolol and Atenolol (Smith & Reynard, 1995).

Another type of antihypertensive medication is the angiotensin-converting

enzyme inhibitors (AI). AIs are generally well tolerated and the most common adverse

effect is chronic cough. The mechanism of action of AIs is on the Renin-Angiotensin-

Aldosterone System (RAAS). Briefly, the RAAS is a key player in the regulation of

human BP. Renin is an enzyme that is found in the kidney and responds to a drop in BP,

stimulation of the SNS, or decreased extracellular sodium concentration. Renin is the

catalyst for the conversion of angiotensin I to potent, vasoconstricting, angiotensin II.

Angiotensin I is converted to angiotensin II by an enzyme found in the lung, angiotensin-

converting enzyme. The system assists the body in maintaining BP. In hypertension,

where there may be abnormally high levels of SNS activity or abnormal renin activity,

AIs work to disrupt the conversion of angiotensin I to angiotensin II (Porth, 1998).

Types of AIs include Captopril, Enalapril, Fosinopril, Rimipril, Quinapril, and Benzepril

(Smith & Reynard, 1995).









Biosituational Factors Associated with High BP

Alterations and/or uncompensated increases in SNS activity in hypertensives may

cause physical signs and symptoms. As described, increased SNS activity and

hypertension are often characterized by an increased heart rate, cardiac output, and renal

vascular resistance. These effects increase BP, flush the skin, increase fatigue, increase

heart rate, and a cause a "pounding or racing" heart (Seeley et al., 1998).

The SNS also promotes numerous metabolic effects throughout the body. These

effects include: enhanced metabolic rate of body cells, increases in blood glucose levels,

mobilization of fats to be used as fuels, and increased mental alertness via stimulation of

the reticular activating system (RAS) of the brain stem. Additionally, increased SNS

activity may promote smooth muscle cell growth and increase the likelihood of

atherosclerotic lesions and the development and/or acceleration of hypertension (Grassi

et al., 2000).

A number have studies suggest that both normotensives and hypertensives have

symptoms associated with fluctuations in their BP levels (Dimenas et al., 1989;

Pennebaker et al., 1982). In a study by Pennebaker et al. (1982), young, normotensive

subjects were evaluated to see if symptoms correlated with fluctuations in BP. Within

subject analysis found that 77% of the subjects had at least one significant symptom-SBP

correlation. Interestingly, the within-subject correlation varied from subject to subject,

indicating that different people perceive different symptoms during fluctuations in BP.

Despite the individual variations, however, symptoms of heavy breathing, pounding

heart, and fast pulse tended to be high for the majority of subjects. In contrast, another

study reported that hypertensive subjects experienced more emotional distress and









cardiac and respiratory symptoms (i.e., sweating, flushing, dry mouth, coughing,

dizziness, and dyspnea) (Dimenas et al., 1989).

BP Variability

BP is labile and normally fluctuates in response to both behavioral and

biosituational factors. These include activity level, posture, emotional state,

communication pattern, bodily function, and internal or external environment. People

with hypertension display significantly greater 24-hour variations in mean arterial

pressure than do normotensives (Mancia, Di Rienzo, & Parati, 1993). In our laboratory,

for example, the range of SBP of 10 hypertensive subjects varied from a minimum range

of 19 mmHg to a maximum of 56 mmHg. BP variability is influenced by both

biosituational and behavioral factors, presumably through central modulation of

autonomic drive to the heart and sympathetic blood vessels. This may be due to greater

pressor responses to emotional and other behavioral stimuli due to an increased central

emotional reactivity in essential hypertensives (Esler, 2000).

Factors such as dietary intake, gender, ethnicity, alcohol/caffeine intake, stressors,

seasonal variations, circadian fluctuations, cocaine and similar drug use, tobacco use, or

others may effect BP fluctuations (Campbell, McKay, Chockalingam, & Fodor, 1994;

Gellman et al., 1990). Brondolo et al. (1999) noted similar findings when they

investigated the effects of workday communication patterns on physiologic parameters.

It was found that naturally occurring interpersonal interactions were associated with

increases in SBP and heart rate.

Headache

Several studies have assessed whether or not the symptom "headache" was

related to BP levels. Kruszewski, Bieniaszewski, Neubause, and Krupa-Wojciechowski









(2000) reported that although 30% of stage 1 and2 hypertensive subjects (N = 150)

experienced headache during 24-hour ABPM, headache was not associated with BP

elevations, mean BP levels were not significantly higher than those during headache-free

periods, BP means 1 hour before and 1 hour after the headache were not significantly

different, and in the majority of hypertensives, the maximal BP values were recorded

outside the headache periods. Dimenas et al. (1989) similarly reported that hypertensive

subjects did not complain of headaches, as compared to other studies which show that

headache is more frequent in patients with hypertension (Bulpitt, Dollery, & Came,

1976). Headache has been speculated to be related to increased pressure and stretching

of the vessels of the dura at the base of the brain (Seeley et al., 1998).

Mood/Communication Pattern

Mood has been reported to be associated with BP. Positive mood accounted for

6% of the within subject variance for systolic and diastolic BPs (Gellman et al., 1990).

Negative mood accounted for 8% of the within subject variance for systolic and diastolic

BPs. The BPs were generally higher during the positive and negative mood states and

were lowest during a neutral mood state. Mood was classified into three categories: (a)

neutral mood (i.e., content); (b) negative mood (i.e., tense, annoyed, upset, angry); and

(c) positive mood (happy and smiling). In previous studies, it was reported that primarily

negative mood was associated with increases in BP (Brondolo, Karlin, Alexander,

Borrow, & Schwartz, 1999; James, Yee, Harshfield, Blank, & Pickering, 1986).

Communication patterns have also been associated with increases in BP.

Brondolo et al., (1999) reported that interacting with the public, supervisor, or coworker

within the prior 15 minutes of BP measurement had an stimulatory effect on BP and

cardiovascular reactivity in normotensives and hypertensives. Elevated BP responses to









positive or negative mood or communication patterns may elicit a cardiovascular

response, similar to the defense reaction hypothesis proposed by Folkow (1982).

Anger, Hostility, Stress, and Anxiety

Durel, Carver, Spitzer, Llabre, Weintraub, and Saab (1989) examined BP levels

and dispositional anger and hostility in 135 African Americans and Caucasion male and

female normotensives and unmedicated mild to moderate hypertensives. Using ABPM,

this study revealed that cognitive anger and state-trait anxiety were strongly associated

with higher SBP and DBP levels at work. In this study, women showed significant

positive relationships between hostility, anger, and anxiety and elevated BP at work.

Male subjects showed no association between anger measures and ABPM levels.

Shapiro, Goldstein, and Jamner (1996) examined the association between cynical

hostility, anger, defensiveness, and anxiety on BP in African American and Caucasion

college students. This study reported that high-hostile African American subjects had

higher SBP during the day and at night compared to high or low hostility Caucasion

subjects. African American subjects who scored high on both anxiety and defensiveness

had higher waking DBP. These studies suggest that there is an association between anger

and hostility and higher BP levels. Additionally, these studies suggest that gender,

ethnicity, type of self-report instrument, activity, and other personality traits may

influence the association (Carels et al., 1998). Factors such as anger and stress have been

shown to effect the "fight or flight" response, thereby increasing catecholamine release

and subsequent SNS effects (Seeley et al., 1998).

Environment

A stressful home environment can cause elevations in BP similar to those seen in

the work environment (Blumenthal, Towner, Thyrum, & Seigel, 1995; Carels et al.,









1998). Blumenthal et al. (1995) reported that married women had significantly higher

BP levels than unmarried women, but married and unmarried men had similar pressures.

In a study by Schnall et al. (1992), 262 employed males were studied and it was found

that social support did not affect BP independently, but the association of job strain with

DBP was stronger for the subjects who had low levels of social support.

Mild hypertensive subjects have also been shown to have greater home versus

work differences in BP, as compared to normotensives (Durel et al., 1989; Gellman et al.,

1990). Additionally, Durel et al. (1989) found that there was a significant correlation

among Caucasion and African American women between work related hostility and

anger and BP. This finding may be related to increased or augmented SNS activity in

response to stressors seen in patients with hypertension.

Work characteristics, such as perceived psychological job demands and decision

latitude, may contribute to work-related stress. Job strain is defined as "a combination of

high psychological demands together with low decision latitude." At least 12 studies

have examined job strain and ABPM in a naturalistic environment (Carels et al., 1998).

Theorell, Perski, Akerstedt, Sigala, Ahlberg-Hulten, and Svensson (1988) examined 73

normotensive men and women in six different occupations and found increased SBP

during work hours among those reporting high job strain, relative to those reporting low

job strain. Other studies examined hypertensive and normotensive subjects and

discovered that job strain was related to increased SBP and DBP at work, home, and

during sleep (Schnall, Schwartz, Landsbergis, Warren, & Pickering, 1992; Vrijkotte, van

Dooren, & de Geus, 2000). Elevations of BP at home, work, or stressful job

environments may be related to activation of the SNS and the "fight or flight" response

(Brondolo et al., 1999).









Posture

Various postural positions effect BP levels. For example, in a study performed on

87 normotensive and 44 hypertensive subjects, the effects of posture on BP were

examined. It was found that 33% to 47% of the within-subject variance in SBP and DBP

could be explained by changes in posture. As subjects in this study went from lying

down to sitting to standing, their BP systematically increased (Gellman et al., 1990). The

baroreflex mechanism is a possible physiological mechanism for changes seen through

the effects of posture. This reflex is initiated by pressure-sensitive receptors, located in

the walls of the large arteries of the neck and thoracic regions, carotid artery, and the

aortic arch. The baroreceptors respond rapidly to acute drops or elevations in BP. Upon

standing, gravitational forces push blood downward and blood flow rapidly decreases

from the head and neck regions. Baroreflex stretch receptors sense changes in

pressure/stretch and react, causing a rapid increase in action potentials toward the

cardioregulatory center in the medulla to increase pressure.

Physical Activity

BP levels are profoundly influenced by physical activity levels. Acute physical

activity and/or exercise increase BP levels (Carels et al., 1998). Over an extended period

of habitual exercise, subjects have improved their cardiorespiratory endurance and

eventually lower resting BP and control hypertension (Jessup, Lowenthal, Pollock, &

Turner, 1998). Physical activity acutely raises BP due to the increased aerobic activity,

which increases oxygen demand, blood flow, cardiac output, and BP (Seeley et al.,

1998).









Lifestyle Factors: Smoking, Caffeine, and Sodium Intake

Laboratory studies suggest that smoking a cigarette results in an immediate and

marked increase in BP. In addition, studies have shown that ABP is higher throughout

the day in smokers compared to nonsmokers (Groppelli, Giorgi, Omboni, Parati, &

Mancia, 1992), particularly for those smokers who have consumed caffeinated beverages

(Narkiewicz et al., 1995). Smokers also tend to have much more BP variability than do

nonsmokers. Caffeine increases BP levels and potentiates cardiovascular and

neuroendocrine effects of stress in both habitual and light consumers (Lane, Adcock,

Williams, & Kuhn, 1990). Hypertensive subjects, in contrast to normotensives,

displayed significant increases in SBP and DBP after consumption of coffee. This is due

to the vasoconstricive properties of the drug caffeine (Hartely et al., 2000; Rakic, Burke,

& Beilin, 1999). A review of literature on sodium intake and BP reported that higher

intake of sodium is associated with higher BP levels. This response may be due to the

physiological water-conserving effects of sodium, thereby increasing blood volume and

BP (Chobanian & Hill, 2000).

Type A Personality

The Type A individual is characterized by feelings of time urgency, impatience,

hostility, aggressiveness, and competitiveness. The Type A personality has been

associated with increased risk of coronary heart disease. Type A individuals exhibit

higher cardiovascular responses in the natural environment, but only under certain

circumstances (i.e., stressful situation, job strain). Type A individuals have higher heart

rates and BP levels and greater BP variability than Type B individuals (Carel et al., 1998;

Steptoe, 2000). This response is most likely related to Type A individuals having

increased reactivity of the SNS and therefore continual "defense reactions."









In summary, BP is affected by numerous biological, situational, and behavioral

factors. Research studies have shown relationships between these factors and BP

variablity (Brondolo et al., 1999; Carels et al., 1988; Durel et al., 1989; Gellman et al.,

1990; James et al., 1986; Lane et al., 1990; Theorell et al., 1988). Despite the growing

research literature on relationships between biosituational or behavioral factors and

higher BP levels, it is widely held that high BP is a relatively asymptomatic event.

BP Awareness and Estimation

Discrimination of physiological processes has been of interest to researchers for

some time. Laboratory procedures have been developed to assess a subject's accuracy of

physiological parameters. Discrimination of heart rate, BP, skeletal muscle tension, and

blood glucose (Barr et al., 1988; Greenstadt et al., 1986) has been reported.

Discrimination of BP by hypertensive patients is of interest to researchers and clinicians

because hypertension is considered a relatively "silent" disease in which immediate

sensory consequences are not available to the individual. The development of procedures

that facilitate detection of BP changes may be useful in the management of hypertension.

According to Cinciripini, Epstein, and Martin (1979), techniques used to facilitate BP

discrimination should utilize procedures that are easily applied in the natural

environment and not too disruptive to the patient's lifestyle.

In the clinical setting, patients with high BP often report that they can identify

when their BP is higher then normal. Often these patients are correct in their awareness

and it has led them to receive treatment based on their physiological measurements after

subjective reporting. Patients often provide clues to their high BP through such

statements as, I just don't feel right," "I feel pulsing or throbbing in my head," or "I

feel hot and tense." While it seems clear that some people are better at sensing high BP,







39

the question remains as to why some people are able to do this while others are not. One

potential hypothesis is that patients with high BP have a higher SNS output and are aware

of symptoms relating to this physiologic phenomenon. While there is no direct link

between BP estimation and SNS activity, there are studies that show elevated SNS

neurotransmitters in patients with high BP (Rahn et al., 1999).

Individuals, both normotensive and hypertensive, may estimate their BP levels by

using both internal sensory and external situational information (Barr et al., 1988).

Estimations and beliefs about BP levels may or may not be accurate, but they are

important because people act upon them. In fact, Pennebaker et al. (1982) suggest that

variations in BP are correlated with different symptoms and that a person can monitor his

or her BP by monitoring symptoms. In studies where both normotensive and

hypertensive people were asked to estimate their BP levels, estimated BP was strongly

associated with symptoms and moods (Baumann & Leventhal, 1985) and with feelings of

physical tenseness and physical activity (Fahrenberg et al., 1995).

Several studies tested whether or not people can accurately estimate their BP.

The findings have been fraught with much speculation and conflicting results (Barr et al.,

1988; Baumann & Leventhal, 1985; Brondolo et al., 1999; Cinciripini et al., 1979;

Fahrenberg et al., 1995; Greenstadt et al., 1986; Luborsky et al., 1976). An important

variable among these studies was the addition of a feedback intervention.

Clinical Relevance of BP Awareness and Estimation

The question of what is a good level of accuracy in estimating BP has not

necessarily been answered with a definitive number. However, several studies examine

BP and coronary event outcomes. For example, studies assessing the effects of BP

reduction and outcomes found significant associations between relatively small







40

reductions in usual BP (5, 7.5, and 10 mmHg) and 34%, 46%, and 56% less stoke and at

least 21%, 29%, 37% less coronary heart disease (MacMahon et al., 1990). Therefore,

even incremental changes or awareness in BP may be a good outcome of BP estimation

research. Additionally, several studies have found that awareness of BP level is a

predictor of health outcomes in patients with hypertension (Asai et al., 2001; Hyman &

Pavlik, 2001). Therefore, it is clinically important for patients to be more aware of their

health status and BP.

BP Estimation Without a Feedback Intervention

Only two studies address the question "Can people estimate their BP without any

type of feedback or training intervention?" Table 2-1 describes the sample descriptions,

methods, and findings of each study. In both studies, subjects were generally and

statistically inaccurate in estimating their BP correctly. Interestingly, perceived BP was

associated with symptoms and moods, rather than with actual BP in a majority of

subjects. Although some participants were better estimators than others, no differences

among subject characteristics were found (Baumann & Leventhal, 1985; Fahrenberg et

al., 1995).

Fahrenberg and his colleagues (1995) assessed whether subjects' estimation of

BP was related to various self-assessments (feeling tense, physical activity, feeling

nervous) or actual BP or heart rate. This research inquiry involved 51 hypertensive

(defined by WHO criteria) male subjects, ages 22 to 60 years and a second group of 30

volunteer hypotensive or normotensive student subjects ages 20 to 28 years. The

hypertensive group was enrolled in a rehabilitation center and was simultaneously

receiving exercise therapy, health education, group therapy, and relaxation training. The

hypertensive group participated in 3 days of psychological and physiologic monitoring.









The first 2 days were consecutive and the 3rd day was approximately 14 days after the

first days. The normotensive/ hypotensive group participated using a SpaceLabs 90207

ambulatory BP monitor (SpaceLabs, Inc, Redmond, WA). Personality assessments and

self-evaluations of physical symptoms were also collected. A programmable pocket

computer (Casio PB 1000) was used by both groups to estimate their SBP (in mmHg)

and record self-report items.

Table 2-1. Research studies: BP estimation without feedback

Authors Sample description Methods Findings
Fahrenberg, 51 hypertensive BP measured every 30 Estimated BP & actual
Franck, males & 30 minutes about 25 times; SBP were poorly
Baas, & Jost normotensive male concurrent diary of correlated; Self-ratings
(1995) and female estimated BP, physical tense & activity were
students. activity, & subjective significantly related to
states. estimated BP.
Baumann & 20 hypertensive & BP measured 2 times per Estimated BP & actual
Leventhal 24 normotensive day for 10 days. BP SBP were poorly
(1985) male & female estimated categorically correlated; 6 out of 41
subjects. (same, higher, or lower subjects had
than usual) & assessed significant correlations
moods/ symptoms. between SBP &
estimated BP;
Estimated BP related
to symptoms.

Within-subject correlations revealed that estimated BP was not related to actual

BP. More extended experience in BP estimation tasks did not enhance the correlation

coefficients in hypertensive patients (day 2, r = 0.32 and day 3, r = 0.27). Estimated SBP

was related to self-reports of symptoms and activity. Stepwise regression indicated that

self-ratings of tenseness and heart rate predicted estimated SBP in hypertensive patients;

however, actual SBP was not related to estimated SBP in any of the regression models.







42

It is unclear whether subjects had variability in their estimations or actual BP and

how often their BP was higher than 140 mmHg (normal BP cut-off point) (JNC VI,

1997). This issue is important because there may be no physiological cues for the patient

to refer to if there are not any higher than normal readings. Differences among the

hypertensive and student groups may have occurred because of differing settings (i.e.,

rehabilitation center versus naturalistic environment) and treatments (i.e., rehabilitation

environment versus no additional training). Although the findings present insight into

awareness of BP, it is premature to generalize these findings to cohorts of either

hypertensive or normotensive subjects because of the presence of potential confounding

variables and differences among groups (e.g., geographic, treatment, instrument).

Baumann and Leventhal (1985) performed a similar study that assessed three

main research questions: (a) whether moods or symptoms are associated with BP in the

work setting, (b) whether people are accurate in assessing their BP levels, and

(c) whether there are dispositional factors that are associated with people's ability to

predict elevated BP. They used a convenience sample and included a heterogeneous

group of 44 insurance company employees (20 subjects with hypertension, 24 subjects

without hypertension). The subjects' actual BP levels were measured two times per day

(in the morning and in the afternoon) for 10 days. The actual BPs were measured using a

mercury column Baumanonometer and a single tube stethoscope. There were six

experimenters who were trained as screener technicians by the Wisconsin Heart

Association. Collected data included the following:

* Actual BP.

* Estimated BP level (i.e., categorical variable-higher than usual, same as usual,
lower than usual).









* Moods/symptoms (i.e., 10-item mood list and a 12-item symptom list regarding
how the subject felt within the last hour).

* Personality measures (i.e., self-esteem scale, private-body consciousness scale).

* BP estimation confidence rating (i.e., 1 = guess, 2 = confident, 3 = very
confident).

* Initial interview questionnaire and poststudy questionnaire (i.e., questions
pertaining to whether subjects can tell if BP is up or down).

Baumann and Leventhal (1985) found that only 6 out of 41 (15%) correlations of

actual to predicted BP were statistically significant (p = 0.01) with an accuracy

correlation "r" of greater than 0.14. It was not clear how the researchers computed the

numerical estimated BP levels, as estimated BP in this study was a categorical variable

(i.e., higher, same, or lower). The results also show that BP predictions and symptoms

were correlated more strongly (56% at p = 0.05) than actual BP to predicted BP (15% at

p = 0.05). Interestingly, subjects claimed to be fairly confident in the BP predictions,

with a mean confidence rating of 2.38 out of a possible 3.

In summary, both studies found that people are generally inaccurate in estimating

their BP. Additionally, both studies reported that people estimate their BP higher when

they are experiencing symptoms that they associate with high BP. These studies provide

a glimpse into the question of whether people are aware of their BP.

BP Estimation With a Feedback Intervention

Other studies have been undertaken to answer the questions "Are people accurate

in judging their SBP?" and "Does feedback improve estimation?" Table 2-2 describes

studies that examined BP estimation and provided subjects some type of feedback

intervention.









Table 2-2. Research studies: BP estimation with feedback


Author Sample Design/methods Findings


Luborsky,
McClintock,
& Bortnichak
(1976)




Cinciriprini,
Epstein, &
Martin
(1979)


Greenstadt,
Shapiro, &
Whitehead
(1986)


Barr,
Pennebaker,
Watson
(1988)






Brondolo,
Rosen,
Kostis, &
Schwartz
(1999)


21 male & female
subjects, 9 of
those taking
antihypertension
medications



18 normotensive
subjects





72 normotensive
subjects


64 normotensive
male & female
subjects








54 mildly-
hypertensive
males


Five sessions of
feedback/no feedback, 2
assigned comparison
groups.


BP measured twice daily
for 20 days/4 weeks. 2
randomly assigned groups
received either feedback
or no-feedback.

Experiment #1: 4 sessions
(1 pre, 1 post, 2 feedback
training).

Experiment #2: 2
sessions (1 feedback, 1 no
feedback).

Experiment #3: single
session of feedback of
DBP

Experimental design with
random assignment to 4
treatment groups (no
feedback, internal
feedback, external
feedback, or
biosituational feedback).
Estimated SBP &
reported symptoms.

Estimated BP & recorded
moods/symptoms an
average of 7.5 times.
Subjects provided prior
BP feedback.


Feedback group
improved after
feedback from 11.5
mmHg to 7.4
mmHg. Accuracy
was maintained over
5 phases.

Feedback group
accuracy improved
& effects were
maintained through
conditions.

Feedback improved
estimation of SBP.
Initial feedback did
not improve
subsequent accuracy
of BP estimations.
Feedback improved
estimation of DBP.


43.8% of subjects
had significant
correlations between
actual & estimated
SBP after the
feedback compared
with 26.6% before
feedback training.


Significant within-
person association
of actual to
predicted BP.









Luborsky et al. (1976) performed a study on 21 subjects (16 normotensives, 5

stage-1 hypertensives) to assess the ability of people to estimate their SBP after being

given feedback of daily BP information. In this study, mean raw error (absolute value)

scores for numerical SBP were compared between baseline and feedback groups.

Feedback, in the form of providing the subject their mean previous SBP readings,

improved the estimation of SBP by 5 mmHg. The authors concluded that the key to

becoming more accurate in estimating SBP is learning your individual range of BP

levels.

Cinciripini and colleagues (1979) studied 18 normotensive student volunteers to

assess the effects of providing BP feedback on the ability to discriminate systolic and

diastolic BP. The subjects were randomly assigned to two groups, one that provided

feedback and one that provided feedback after an extended baseline period. Group 1

consisted of feedback (i.e., the mean of two BP readings for that session) that was

provided to the subjects for five days in a multiple baseline fashion. The procedure

began with an initial screening for BP variability, 5 days of baseline (no feedback), 5

days of feedback, and 10 days postbaseline (no feedback). Group 2 subjects had an

extended baseline period followed by a feedback condition. The subjects were asked to

estimate their systolic and diastolic BP levels twice a day for 20 consecutive days prior to

measuring them using a mercury sphygmomanometer. This study evaluated the

difference between estimated and actual BP using the absolute deviation in mmHg

between the estimate and actual mean daily BP. Those in group 1 improved their ability

to estimate their actual BP after the sequential implementation of feedback. The mean

SBP daily deviation score at baseline for group 1 was 9.6 mmHg and after feedback it

declined to 5.9 mmHg. This improvement continued after the feedback sessions and was









maintained during the no feedback, postbaseline period. Those in group 2 showed no

statistically significant improvement during the extended baseline period; however, their

accuracy level improved after the addition of feedback during the last week of training.

These subjects improved from a mean SBP daily deviation score of 9.0 mmHg to a score

of 3.6 mmHg after feedback was provided (Cinciripini et al., 1979).

Greenstadt and colleagues (1986) performed an experimental study on 72 healthy

normotensive volunteers to assess the benefit of discrimination training on the ability of

normotensive subjects to detect changing levels of their own BP. Overall, this study

concluded that normotensive subjects have relatively no awareness of small BP

variations, but that feedback in the form of "knowledge of results" improves BP

discrimination.

Barr et al. (1988) studied 64 normotensive subjects for 3 sessions (3 months

apart) to assess the effects of internal and environmental feedback on SBP estimation.

This study was unique in that it utilized biosituational feedback methods. Biosituational

feedback involves providing feedback to the patient regarding internal (e.g., actual BP,

symptoms, moods) and external (e.g., environment, posture, diet) factors that occur

during the measurement of BP (Barr et al., 1988). In the feedback phase of the study,

subjects were randomly assigned to one of four groups: no feedback, symptoms/mood

feedback, situational/activity feedback, or biosituational feedback (a combination of the

previous two feedback types). Approximately 71.4% of the subjects in the biosituational

feedback group had significant accuracy correlations, compared with 31.3% in the

symptoms/moods group, 44.4% in the situational group, and 31.3% in the control (no

feedback) group.









Brondolo et al. (1999) provided 54 mildly-hypertensive subjects with their SBP

range after a baseline period. This study found significant within-subject associations of

actual to predicted SBP (p = 0.002) and DBP (p = 0.02) in 54 mildly hypertensive male

subjects. The authors also took into consideration factors that may influence judgments

about BP estimation including home BP monitoring and use of medications. The

findings indicate that, given some information about their previous BP, subjects display a

limited but reliable relationship between their actual and estimated SBP.

In summary, five studies that have provided feedback to people to improve their

ability to estimate their BP have shown an improvement in BP discrimination after

feedback. Different types of feedback have been used to assist subjects in learning to

recognize symptoms, situations, and factors that are associated with their BP levels.

Providing normotensive (Barr et al., 1988; Cinciripini et al., 1979; Greenstadt et al.,

1986) and hypertensive subjects (Brondolo et al., 1999; Luborsky et al., 1976)

knowledge of their actual BP levels has been somewhat successful in improving the

accuracy of BP estimation.

Discussion of BP Estimation Studies

Among the feedback intervention-type studies, all showed an improvement in BP

discrimination after feedback (Barr et al., 1988; Brondolo et al., 1999; Cinciripini et al.,

1979; Greenstadt et al., 1986; Luborsky et al., 1976). In contrast, both studies that did

not provide feedback failed to show associations between actual and estimated BP levels

(Baumann & Leventhal, 1985; Fahrenberg et al., 1995). However, both studies found

relationships between estimated BP and self-reports of physical symptoms and subjective

state. Limitations for generalizability include the use of normotensive, young-student, or

convenience samples; the amount and frequency of the feedback interventions and/or BP









estimations; and the lack of application to real-life situations and circumstances of

American hypertensive patients. If patients can be trained to recognize when their BP is

elevated, they may be candidates for some further intervention (e.g., biofeedback

training) to help control their BP. However, more research is needed to conclusively

state that patients with hypertension are either accurate or inaccurate in estimating their

SBP levels.

This review of research provides support for using feedback methods to improve

the ability to estimate BP and suggests that BP awareness may be improved in some

people using feedback methods. The limited number of studies studying hypertensive

persons with high BP suggests that more research is needed to further assess the effects

of BP awareness feedback training among this group. Research is needed to evaluate

clinical outcomes of BP awareness training, such as BP control, patient motivation and

compliance, cost-effectiveness, and morbidity and mortality.

Over the past several years, changes have occurred in health care that have made

patients more than mere passive participants of their healthcare. Patients are much more

willing and able to learn more about their health and well-being than previous

generations (Strohecker, 1999). Teaching people about their BP and BP patterns is an

effective way to improve health of patients and empower people with hypertension to

have more control over their own life and health (Healthy People 2010, 2003). This

review of literature suggests that BP feedback interventions may be an effective means to

teach people how to learn more about their BP patterns and when their BP is elevated.

While this research is promising, more inquiry is needed to decide if training patients

with hypertension can improve their awareness of their high BP episodes and if this

training will ultimately improve healthcare outcomes.









Educational Level and Health Disparities

Major disparities exist among population groups, with a disproportionate burden

of death and disability from cardiovascular disease in minority and lower socioeconomic

populations. Health disparities are defined as differences in the incidence, prevalence,

mortality, and burden of diseases and other adverse health conditions that exist among

specific population groups in the United States. Several research studies have reported

that higher educated people tend to be healthier and have improved outcomes to

treatments, whereas people of lower socioeconomic status tend to have more adverse risk

factors and poorer health (Myllykangas, Pekkanen, Haukkala, Vahtera, & Salomaa, 1995;

Winkleby et al., 1990; Winkleby, Jatulis, Frank, & Fortmann, 1992). For example, data

from the NHANES III study showed that there were highly significant differences in BP,

body mass index (BMI), and physical inactivity for both African- and Mexican-American

women compared to white women when educational level and ethnicity were adjusted

for (Winkleby, Kremer, Ahn, & Varady, 1998). Disparities also exist in the prevalence

of risk factors for cardiovascular disease. Lower educated persons and racial and ethnic

minorities have higher rates of hypertension, BMI, physical inactivity, and non-HDL

cholesterol, tend to develop hypertension at an earlier age, and are less likely to undergo

treatment to control their high BP (NIH Online, 2003). In a study by Goldman and

Smith (2002) differences in treatment adherence by education level are examined in

patients with HIV and diabetes. It was found that patients with higher socioeconomic

status and higher educational levels had improved treatment adherence and outcomes. In

this study, the more-educated patients were more likely to adhere to therapy and have

better self-reported general health. The less-educated patients were more likely to switch

treatments, which led to worsening general health. The authors assert that the large









differences in health outcomes exist, not solely because of poor access to care or poor

health behaviors, but because of differences in educational level (Goldman & Smith,

2002).

Ambulatory BP Monitoring

Ambulatory BP monitoring (ABPM) is a naturalistic BP measurement technique

that has been evolving over the past 30 years. It is a method that allows a clinician,

patient or researcher to monitor multiple BP readings over a 24- to 48-hour period.

These devices can measure BP over time and introduce minimal intrusion into the

person's daily routine. ABPM is used clinically to assess and diagnose types of

hypertension, evaluate pharmacologic and/or nonpharmacologic therapies, and monitor

resistant and/or borderline hypertension.

Ambulatory BP monitoring has now become an established research tool in

clinical trials. The use of ABPM decreases threats to external validity and the potential

"white coat" effect of observers on physiological and psychological responses.

Oscillometric monitors measure SBP, mean arterial pressure (MAP), and heart rate (HR),

from which DBP, pulse pressure (PP), and average 24-hour BP, diurnal changes, BP

Load (percentage of systolic and diastolic readings greater than 140 and 90 mmHg during

the day and greater than 120 and 90 mmHg during the night), and BP variability (the

standard deviation of the average 24-hour daytime and nighttime measures) can be

calculated. Ambulatory BP measurements correlate with the extent of target organ

damage or cardiovascular risk. For example, Verdecchia (2000) reported that ambulatory

SBP, DBP, and PP were independently and directly associated with cardiovascular risk.

While the use of the ABPM is minimally intrusive to the person, it may pose

comfort issues such as annoyance from the beeping sound, weight of the ABPM device,







51

and bulkiness of the device. Over the past several years, improvements have been made

to the devices to make them more "user friendly" and comfortable for subjects to wear

for longer periods of time. Adherence has been shown to be enhanced following

empathetic discussion and demonstration of the device. The safety of ABPM techniques

have been established and complications are rare (NHBPEP-ABPM, 1992).

A typical, fully-automatic ABPM device is battery-driven and consists of an arm

cuff that can be programmed to inflate automatically throughout a 24- to 48-hour period.

BP is determined in the arm by detection of (a) Korotkoff sounds by one or two

piezoelectric microphones under the cuff (ausculatory method) and (b) oscillations

transmitted from the brachial artery to the cuff (oscillometric method). The Spacelabs

90207 ABPM device (Spacelabs, Inc, Redmond, WA) measures BP using the

oscillometric technique. Auscultatory and oscillometric techniques have not been

rigorously compared to each other to see if one is more preferable for ambulatory BP

monitoring. However, the auscultatory technique is more sensitive to environmental and

distracting noises, such as automobiles and large machinery. Oscillometric techniques

detect systolic and mean BP and use algorithms to calculate diastolic BP. This may be a

weakness as these algorithms are not appropriate for all subjects. Additionally,

oscillometric methods are affected by muscle artifacts and tremors generated beneath the

cuff. To avoid invalid or erroneous readings, the device should be calibrated properly

and the cuff should be fit to the subject prior to use. In short, ABPM is a mature and

clinically appropriate method for obtaining multiple, naturalistic ambulatory BP readings

over a period of 24- to 48-hours (NHBPEP-ABPM, 1992).









Summary

In summary, hypertension, specifically high SBP, continues to be a major

predictor of morbidity and mortality of people in the United States and worldwide. As

many as 50 million American people are estimated to have hypertension (AHA, 2003a).

Isolated systolic hypertension is prevalent among the elderly and people greater than 50

years of age (Franklin et al., 2001). Current diagnostic and treatment modalities have

been wrought with difficulties due to a variety of physiologic, psychologic, socio-

economic, and practical factors. Current research suggests that the sympathetic nervous

system plays a major role in the development and/or maintenance of hypertension

(Rumantir et al., 2000). Activation of the SNS leads to a documented

psychophysiological "fight or flight" response and associated manifestations. It is

unknown whether high BP is associated with symptoms; however the majority of current

knowledge suggests that it is an asymptomatic phenomenon. Despite the overwhelming

support that hypertension is an asymptomatic disease, studies using BP and biosituational

feedback have shown that people can be trained to become more aware of their BP

levels. It is unknown whether the combination of ambulatory BP methods and

biosituational self-awareness training improves subjects' ability to recognize when their

BP is elevated. Due to the recent surge of knowledge regarding the sympathetic nervous

system's connection with hypertension, it seems likely that some people, if not all

people, could be trained to become more aware of the increased SNS activity.















CHAPTER 3
PROCEDURES AND METHODS

The purpose of this research was to determine if subjects with hypertension could

improve their estimation of their SBP after an ambulatory BP feedback and biosituational

self-awareness training intervention.

Research Design

A prospective cohort, repeated measures, pretest/posttest design was employed

for this study. A repeated measures design allows subjects to serve as their own control

and within-subject differences to be analyzed. The design, analysis groupings, and data

measured are graphically displayed in Table 3-1.

Population and Sample

The population under investigation was adult hypertensive persons, aged 21 to 65,

in the northern Florida area. Subject recruitment was done through both flier advertising

and BP screening. The investigator offered BP screening over the course of a 12-month

period at various locations. Before BP was measured, potential subjects were told that

they would be offered the opportunity to take part in a research study if they qualified.

BP was measured twice 2 minutes apart after the subject sat quietly for 3 to 5 minutes. If

the BP measurements differed by more than 5 mmHg, an additional BP measurement

was taken. The initial BP screening was obtained by averaging the two BP readings that

agreed within 5 mmHg. Subjects who met the inclusion and not the exclusion criteria

were asked to participate in the study. Every attempt to include diverse participants









Table 3-1. Description of design, analysis groupings, and data measured

Group Hypothesi Pretraining Training Posttraining
s (H)
Adult hypertensives H 1 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
(total sample) mean AD mean AD
Adult hypertensives H 2, H 3 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
college educated MI MI
Adult hypertensives H 2, H 3 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
noncollege- educated mean AD mean AD
Adult hypertensives H4 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
BMI < 30 MI MI
Adult hypertensives H4 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
BMI > 30 MI MI
Adult hypertensives H5 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
male MI MI
Adult hypertensives H5 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
female MI MI
Hypertensives < 48 H6 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
years of age MI MI
Hypertensives 48 H 6 ASBP, ESBP, ASBP, ESBP ASBP, ESBP,
years of age MI MI
Antihypertensive H7 ASBP, ESBP ASBP, ESBP ASBP, ESBP
medication nonusers
Antihypertensive H 7 ASBP, ESBP ASBP, ESBP ASBP, ESBP
medication Users__ _
Note: ASBP represents actual SBP, ESBP represents estimated SBP, mean AD
represents mean absolute difference, and MI represents mean improvement.

(i.e., gender, race, socioeconomic, age, and ethnicity) was made. To determine the

sample size, it was estimated that subjects could improve their estimation of SBP by

decreasing the difference by half. For example, if the mean difference between the actual

and estimated SBP was 10 mmHg on day 1, this difference would drop to 5 mmHg.

Assuming that the deviation of the difference was 4.0 mmHg, setting an alpha of 0.05,

and using a 2-tailed test, 8 subjects would be required to achieve at least 80% power.

Recognizing that subjects may not be able to improve their estimation this much with

only a 2-day training period, a second determination of sample size was completed based

on an improvement of 2 mmHg, the smallest effect that would be important to detect.









Again, if on day 1 the mean difference between the actual and estimated SBP was 10

mmHg and the mean difference on day 4 was 8 mmHg, this would constitute an

improvement of 2 mmHg. Assuming a standard deviation of the difference to be 4.0

mmHg, setting an alpha of 0.05, and using a 2-tailed test, 34 subjects would be required

to achieve at least 80% power. Recognizing that these are estimates and there are no data

suggesting the appropriate effect size to use, 42 subjects were recruited for study to allow

for attrition and incomplete data.

To ensure that subjects would have adequate variability to be able to detect

differences, we randomly selected ambulatory BP data from 10 hypertensive subjects in

Dr. Yucha's research study. For these 10 subjects, the average daytime range in SBP was

33.2 mmHg, ranging from a minimum of 19 to a maximum of 56 mmHg. Therefore, we

felt confident that subjects would have adequate variability in their BP to detect

differences (unpublished BP variability data, 2001).

Inclusion and Exclusion Criteria

The specific inclusion criteria were as follows:

* men or women 21 to 65 years diagnosed with hypertension or taking
antihypertensive medications, living in the North Florida area.

* ability to come to the research office at least four times.

* ability to speak and understand English.

* able to verbally communicate with intact memory.

* ability to read English at an eighth grade level or greater.

Subjects who could respond to requests for participation were considered to have

adequate communication skills and memory ability. Subjects were excluded from the









study if their history demonstrated significant cardiovascular, renal, or psychiatric

diseases. There was no exclusion of subjects based on gender or race.

Setting

The setting for this study was a county located in Northern Florida. Initially, the

subjects were screened in the laboratory or field setting. The pretraining, training, and

posttraining sessions occurred in the subjects' natural environment during daytime hours

while the subjects were awake.

Research Variables and Instruments

Demographic Data Sheet

The demographic data sheet included information regarding age, gender, race,

marital status, how long with diagnosis of hypertension, height, weight, body mass index

(BMI), and education.

Health History Form

The health history form included yes/no type questions regarding the presence or

absence of health conditions including high BP, diabetes, heart and cerebral disease,

psychiatric disorders, and other chronic diseases. Additionally, questions regarding past

or present smoking, alcohol use, high cholesterol, exercise level, medications, and family

cardiovascular health history were included.

Ambulatory BP Monitor

Naturalistic ambulatory monitoring of BP in human subjects was preferred in this

study because it enhances the generalizability of the findings to outside of the laboratory

setting and it does not interfere with most of the subjects' usual daily activities. The

SpaceLabs ABPM (Model 90207, SpaceLabs, Inc., Redmond, WA), an automatic

noninvasive oscillometric recorder, was used to collect SBP data. This monitor measures









BP by detection of oscillations transmitted from the brachial artery to the cuff. The

monitor was equipped with four different size adult cuffs. A SpaceLabs (Model 9029,

Redmond, WA) Data Interface Unit was used for data retrieval and report generation.

The ABPM can be programmed to display the BP readings on its' LCD screen

immediately after measurement (i.e., unblinded) or not to display the BP readings (i.e.,

blinded). This feature worked well for this study, as different time periods required

"blinding" or "unblinding" of the LCD screen. The reliability of the SpaceLabs ABPM

device has been studied extensively over the last few years. Correlation coefficients

between two sets of readings have ranged between 0.72 and 0.93 for SBP, indicating that

the reliability is acceptable (Pickering et al., 1994). Pickering et al. suggest that at least

five or six readings would give an adequate representation of the average pressure in a

particular setting such as work or home. In addition, a sampling frequency of one

reading every 30 to 60 minutes has been suggested to adequately describe average SBP

levels in different settings. This instrument has a high level of accuracy and clinical

performance and meets Association for the Advancement of Medical Instrumentation

guidelines and the guidelines of the British Hypertension Society (O'Brien, Atkins, &

Staessen, 1995). Artifactual readings were eliminated using the Casadei procedure, a

standard editing criteria (Winnicki, Canali, Mormino, & Palatini, 1997). Similar to other

editing criteria, the Casadei procedure eliminates measurements that fall outside 50 to

240 mmHg for SBP, 40 to 140 mmHg for DBP, 40 to125 beats per minute for heart rate,

and 20 to 100 mmHg for pulse pressure.

Rigorous calibration of the monitor was made prior to ABP monitoring. A

calibration procedure comprised of three calibration readings taken simultaneously with a







58

mercury column sphygmomanometer and the ABP monitor, by means of a "T-connector"

between the two instruments. Readings for both SBP and DBP agreed within 5 mmHg of

one another on all three attempts.

For the purpose of this study, the ABPM was initialized to measure BP every 30

minutes. Actual ambulatory BP measurements were recorded as numerical continuous

response variables. After measurement of ambulatory BP, BP data were downloaded

using SpaceLabs Data Management Software (Redmond, WA) and the data.

Actual BP

Actual BP was a continuous variable that was measured using a SpaceLabs

Ambulatory BP Monitor (Model 90207, SpaceLabs Inc., Redmond, WA).

Estimated Systolic BP

Estimated SBP was a continuous numerical variable that was estimated by the

participant in mmHg and was based on the guideline provided to the participant.

Participants were also invited to circle the range of SBP that they thought their SBP was

in at the time of cuff inflation and BP measurement. This was done to improve the

conceptualization of the participant to estimating his/her own SBP. If range information

was the only method of estimating for the subject, the average of the range was computed

and entered as the subjects' estimation of SBP.

Absolute Difference

The absolute difference (AD) is defined as the absolute value of the mean

difference. The absolute difference was calculated for mean actual SBP day 1, mean

estimated SBP day 1, mean actual SBP day 4, and mean estimated SBP day 4.









Mean Improvement

The mean improvement is defined as the absolute value of the mean difference of

day 1 (mean actual SBP minus mean estimated SBP) minus the absolute value of the

mean difference of day 4 (mean difference of actual SBP minus estimated SBP).

Pre- and Posttraining SBP Estimation Form

The pre- and posttraining SBP Estimation Form provides subjects with a

guideline for SBP estimation that is based on the classification defined by the Joint

National Committee on Prevention, Detection, Evaluation, and Treatment of High BP

(JNC VI, 1997). This tool categorizes SBP based on the JNC VI (1997) classification

and provides categorical descriptions of each range of SBP category. This serves to help

subjects conceptualize their SBP, so that they can estimate their SBP level. Subjects are

instructed to write an estimate of what they think their SBP level is at the start of cuff

inflation. Subjects were instructed that they may circle the range of where they think

their SBP falls, if this was more understandable for the subject.

SBP Estimation Training Form and Self-Awareness Checklist

The training form is a form that is used during days 2 and 3. One form was used

for each BP measurement/estimation. The form consists of an area for the subject to

write the time of BP measurement, estimated SBP level (subject estimates), and actual

SBP level (from the monitor). The Self-Awareness Checklist is a yes/no checklist. It is

made up of 38 mood, symptoms, and situation items. This checklist has been adapted

from research on physical symptoms and factors relating to BP (Barr et al., 1988;

Brondolo et al., 1999; Gellman et al., 1990).









Demographic Variables

Demographic characteristics of subjects were examined by nine indicators:

gender, race, education, marital status, age, height, weight, body mass index, and how

long with diagnosis of hypertension.

Gender. Gender was a categorical variable coded as male or female.

Race. Race was a categorical variable coded as White, Black, Hispanic, Asian,

and other.

Education. Education was categorized into seven groups according to the number

of years of formal education which the participants completed: less than 7 years, junior

high school (grades 7-9), some high school (grades 10-11), high school graduate, some

college or technical school, college graduate, and graduate school (master's degree or

beyond). For data analysis purposes, education was further compressed into two

variables: H.S./technical school and college educated.

Marital status. Marital status was coded into one of four categories reflecting the

status of married, widowed, divorced/separated, or never married.

Age. Age was recorded as actual years and was coded into five categories

reflecting years of age: 21-30, 31-40, 41-50, 51-60, 61-65. For data analysis purposes,

age was further compressed into two categories: > 48 years of age and < 48 years of age.

Weight. Weight was a continuous numerical variable that was recorded in

kilograms (kg).

Height. Height was a continuous numerical variable that was recorded in

centimeters (cm).

Body Mass Index (BMI). BMI was calculated as the ratio of the weight in kg to

the square of the height in meters.







61

Length of time since diagnosis of hypertension. Length of time since diagnosis of

hypertension was categorized as follows: less than 5 years, 5-10 years, 11-20 years, 21

years or more.

Health Status Variables

Four indicators were utilized to identify the health status, family cardiovascular

health history, and the use of prescribed and nonprescribed medicines. These variables

included (a) existence of health problems, (b) number and type(s) of medications used

daily, (c) family cardiovascular health history, and (d) lifestyle factors. Below is a

description of these variables.

Health problems. The participant was asked to identify his or her health problems

from a list of different illnesses. The answer was coded zero when the problem did not

exist and one if the problem existed.

Use and type of medications. The use of all types of medications was a

categorical variable that was coded zero if there were no medications used and one if the

participant used medications on a daily basis. If the answer was yes, the participant was

asked to name all prescribed and nonprescribed medications that are used daily. For data

analysis purposes, the medication variable was further described to account for

differences among types of medications and antihypertensive medications. A variable

coded as "htntype" was created and was coded as 0 if they were taking no hypertensive

medications, 1 if they were using ace inhibitors, 2 if they were using calcium channel

blockers, 3 if they were using beta blockers, 4 if they were using diuretics, 5 if they were

using other antihypertensives, and 6 if they were using 2 or more antihypertensive

medications.









Family cardiovascular health history. Each participant was asked to identify

illnesses that his or her blood relatives have had or currently have. Family

cardiovascular health history was coded into five categorical variables including heart

attack, high BP, stroke, diabetes, and high cholesterol. The answer was coded zero if

there was no family history of the disease. The variable was coded 1 if there was a blood

relative with one of the identified illnesses, 2 if there were 2 identified illnesses, 3 if there

were 3 illnesses chosen, 4 if there were 4 chosen, and 5 if there were 5 illnesses chosen.

Lifestyle factors. Lifestyle factors were considered questions relating to alcohol

use, caffeine use, exercise level, and cholesterol elevation. The responses were coded

zero if the respondents chose no and one if the respondents chose yes.

Table 3-2. Instruments used and variables measured during the study periods

Instrument Variables
ABP Monitor Actual SBP
Pre-/Posttraining Form Estimated SBP
Training Form/Self-Awareness Estimated SBP
Checklist Actual SBP
Biosituational factors

Demographic Data Sheet Gender
Race
Education
Marital status
Height
Weight
BMI
Time with hypertension
Veteran status
Age
Date of Birth
Health History Form Personal history of cardiovascular, renal,
liver, thyroid diseases, diabetes mellitus,
caffeine, alcohol and tobacco use, exercise,
medication usage, and family history.









Classification of Adult BP

The criteria for classifying BP as defined by the Joint National Committee on

Prevention, Detection, Evaluation, and Treatment of High BP (JNC VI, 1997) was used

to assist subjects to estimate their actual BP. Table 3-3 shows the classification for adult

BP as defined by the JNC VI (1997).

Table 3-3. Adult BP classification

Category Systolic BP (mmHg) Diastolic BP (mmHg)
Optimal Less than 120 and Less than 80
Normal Less than 130 and Less than 85
High-Normal 130-139 or 85-89
Hypertension
Stage 1 140-159 or 90-99
Stage 2 160-179 or 100-109
Stage 3 180 or greater or Greater than 110

Study Protocol and Procedures

This research consisted of three phases: (a) initial interview and pretraining

measurement and estimation of BP (one day period), (b) ABPM and biosituational self-

awareness training (2-day period) and (c) posttraining measurement and estimation of BP

(1-day period).

Subject Recruitment

After the appropriate institutional review and approval, subjects were recruited

from northern Florida. The investigator recruited participants using fliers and

advertisements that were posted near the University of Florida, the Veterans

Administration clinics, hospitals, and various public areas in the north Florida area.

Recruitment fliers were also sent to female veterans with hypertension in the northern

Florida area. Attempts to include diverse participants (i.e., gender, age, and race) were







64

made. Those subjects who met the inclusion criteria and who did not meet the exclusion

criteria were asked to participate in the study.

Initial Screening Procedures

The initial screening occurred in either the laboratory or field setting. The

procedure for measuring BP was in accordance with JNC VI recommendations, using the

ABPM. To assure that the ABPM readings are valid, calibration of the equipment was

performed. The investigator calibrated the ABPM using simultaneous determinations of

BP by auscultation and a mercury sphygmomanometer (using T connector) and

agreement of at least 3 sequential readings to within 5 mmHg systolic and diastolic was

found (NHBPEP-ABPM, 1992).

The BP measurement began after approximately 3 to 5 minutes of quiet rest,

sitting in a chair. The subject was seated in a chair with his/her back supported and

nondominant arm bared and supported at the heart level. The appropriate cuff size was

determined to ensure accurate measurement. The bladder within the cuff encircled

approximately 80 % of the subject's arm in accordance with JNC VI recommendations

(JNC VI, 1997). The investigator provided the subject with an initialized, programmed

and fitted ambulatory BP monitor. The investigator performed two BP measurements

approximately two minutes apart, in accordance with recommendations of the JNC VI

(1997, p. 12). If these two measures were more than 5 mmHg apart, a third measure was

taken. The average of the measurements were provided to the patient as their "average

BP."

Ambulatory BP Monitoring Protocol

The subject was instructed to refrain from excessive physical exertion and water

activities while wearing the BP monitor. The subject was instructed to keep a regular









sleep and wake pattern and to avoid any unusual physical exertion or excessive stress

during the study period. The subject was instructed that he/she could remove the monitor

for short time periods if these activities were unavoidable. Then, the subject was given

the opportunity to use and become familiar with the ABPM.

Ambulatory BP was measured on an ordinary work, home, or school day for each

subject. To ensure that the subjects were experiencing "usual" symptoms or situations,

subjects were asked prior to beginning each study day how they were feeling on that day

and if they were feeling "well" or "usual." If the subject was not feeling as he/or she

normally feels (e.g., has a cold/flu or other anomaly), the session was postponed until the

following day or a more "usual" day.

To ensure subject safety, subjects were instructed to sit, rest, and call their

primary health care provider in the event that their BP was greater than 180 mmHg

systolic or 110 mmHg diastolic over two consecutive periods. Because of the nature of

the ABPM device, subjects were instructed that they could push the "start" button on the

monitor and measure their BP in more frequent intervals than were programmed. In

addition, subjects were instructed to call their health care provider or seek emergency

care if they experienced any other serious discomforts other than the minimal

discomforts associated with the use of the ambulatory BP monitor. Subjects were

instructed that symptoms such as chest pain, shortness of breath, or numbness or tingling

of face, legs, or arms should be reported immediately to their healthcare provider.

Subjects were fitted with an ABP monitor and familiarized with its use. The

monitor was programmed to measure BP every 30 minutes over a 6-hour period.

Subjects were instructed that they could wear the monitor during their usual awake hours,

generally between the hours of 6 am and 10 pm. Each subject was fitted with a proper-







66

sized BP cuff, fitted according to JNC VI recommendations (JNC VI, 1997). To ensure

that the cuff was not too tight, the investigator inserted a finger between the bladder of

the cuff and the subjects' arm. Subjects were provided an ABPM tote bag or hip strap to

assist in carrying the ABP monitor.

The monitor emits a series of 5 beeps prior to measurement of BP and cuff

inflation. The subject was instructed to listen for these sounds and to hang their arm

freely at their side during cuff inflation. They were also instructed to keep the bladder of

the cuff at or near the level of their heart, to avoid measurement errors. At cuff inflation,

subjects were instructed to estimate their BP. On days 2 and 3, subjects were also

instructed to document their actual SBP as well as their moods, symptoms, and activities

during the BP measurement.

Day 1

After the initial screening for inclusion/exclusion criteria, a convenient meeting

date and time to start the study was arranged. Informed consent was obtained and a copy

of the informed consent and contact information for the investigator and dissertation

chairperson was provided to each participant. Subjects were informed that participation

in this study will not change the way they are treated for high BP. The subject was

instructed to continue doing exactly what his/her doctor has prescribed. Each participant

was advised of his or her rights as a research participant and the right to decline without

penalty. The investigator arranged a time and place for the initial interview, either at the

research office or the subject's home. The investigator instructed the subject about the

study procedures and that data would be collected over a 4-day period. The participants

were notified that there was monetary compensation of $10.00 per day for each day that

was completed.







67

After informed consent was obtained, the subject was asked to answer questions

related to demographics, health status, family history, and medication usage. The entire

interview took approximately 15-30 minutes per subject. After completion of the initial

interview, data were entered into a data spreadsheet for analysis.

When the subject was comfortable with the ABPM operation and function, the

subject started Day 1 data collection period and took the ABPM home, work and/or to

their "natural" environment. The participant was instructed to estimate numerically their

SBP using guidelines from the JNC VI (1997). The LCD screen on the ABPM was

"blinded" (i.e., no BP readings were displayed). The subject was instructed to return to

the clinic the following day with the ABPM, or arrangements for a field visit were made.

Days 2 and 3

On the second study day, day 1 data were downloaded and edited using the

SpaceLabs (Model 9029, Redmond, WA) Data Interface Unit. Data were entered into a

data spreadsheet for analysis. The ABPM was initialized and reprogrammed to display

the BP readings on the LCD screen. The subject was provided information on potential

biosituational factors that may affect BP. The subject was given the opportunity to use

and become familiar with the Training Form/Self-Awareness Checklist. The subject was

instructed to fill out the Self-Awareness Checklist at each BP reading. The subject was

instructed that SBP, DBP, and HR are visible in the LCD screen after each BP

measurement. Next, the subject was asked to look at and write down his or her actual

SBP level as it appears on the LCD screen after each reading. Subjects were instructed to

estimate their SBP in a similar fashion as in day 1, when the cuff began to inflate.

When the subject was confident with using the Self-Awareness checklist and

Training Form, he or she was instructed to wear the ABPM for two consecutive days in









the "normal" environment and perform the instructed tasks every 30 minutes for six

hours each day.

Day 4

On the fourth study day, the subject and investigator met again. The data were

downloaded onto a spreadsheet for analysis. The ABPM was initialized and re-

programmed not to display the BP readings. Similar to day 1, the LCD screen was

"blinded" to the subject (i.e., the BP reading were not be visible to the subject). The

subject was instructed to think about the biosituational factors that occurred during their

SBP measurements and when SBP was high. Subjects were given an opportunity to

assess the biosituational self-awareness factors that were related to high SBPs (according

to individual responses).

Subjects were instructed to wear the ABPM monitor for 6 hours and estimate

their SBP, making decisions based on their biosituational self-awareness factors and BP

readings, during the previous 2 days.

At the conclusion of the study, subjects were instructed to return the ambulatory

BP monitor and all forms to the investigator. Subjects were thanked for their

participation and were given a printed analysis of the 4-day ABPM readings. Each

subject received $10.00 compensation for each day they completed. The subjects

received a total of $40.00 monetary compensation for participation in this study. Study

procedures are outlined in Table 3-4.

Methods of Statistical Analyses

Data were analyzed using SPSS (SPSS, Inc., Chicago, Illinois). Descriptive

statistics were computed to obtain the summary measures for the data addressing the

research hypotheses. Estimated SBP data was obtained from the pre-/posttraining SBP









Estimation Form. Actual SBP measurement data was obtained from the data recorded

using the ABP monitor and the report generated by the SpaceLabs (SpaceLabs, Inc.,

Redmond, WA) Data Interface Software. These data were entered into data files for

analysis using Microsoft Excel (Microsoft Inc.) software and SPSS (SPSS, Inc., Chicago,

Illinois) statistical software. Descriptive statistics were computed to identify the

demographic characteristics of the participants, number and types of medications used,

health problems, and family health history. Study variables (estimated and actual SBP,

absolute difference (AD) of the mean scores of day 1 and 4, and mean improvement)

were summarized and graphed across time. For data analysis purposes, day 2 and 3 were

combined and a total mean score for actual SBP, estimated SBP, and absolute difference

were calculated for the two days. Analysis concerning the relationships between actual

and estimated SBP were performed using paired-samples t-tests. For Hypothesis 1 and 3,

paired-samples t-tests were used to compare the mean improvement between day 1 and

day 4 within groups. For Hypotheses 2 and 4 through 7, independent samples t-tests

were used to compare the means between groups of subjects. See Table 3-1 for a

description of the design, analysis groupings, and data measured in this study.









Table 3-4. Procedures for SBP estimation study

Phase 1: Initial Interview and Pretraining (Day 1)
In laboratory/Field Setting:
Screen for Inclusion/Exclusion criteria
Informed Consent Process
Calibrate & initialize ABPM (BP readings not shown) and determine cuff size
Obtain demographic, health status, health and family health history, and
medication usage data
Provide basic information about SBP
Obtain "average" baseline BP and provide information to subject
Introduction to Pre-/Posttraining Estimation Form and ABPM
Allow subject to practice using SBP estimation form and ABPM
In natural setting:
Subject estimates SBP (LCD blinded) for 6 hours at start of each cuff inflation

Phase 2: Training (Days 2 & 3)
In laboratory:
Initialize ABPM (BP readings shown)
Provide information on SBP Estimation and BSMA factors
Demonstrate ABPM and Training Form/Self-Awareness Checklist
Allow subject to practice using ABPM, BP estimation, and Self-Awareness
Checklist
In natural setting:
Subject estimates SBP for 6 hours at start of cuff inflation
Complete Training Form (SBP estimation, Self-Awareness Checklist, & actual
SBP)

Phase 3: Posttraining (Day 4)
In laboratory:
Initialize ABPM (BP readings not shown)
Instruct patients to think about biosituational self-awareness factors & SBP
feedback while estimating their SBP
In natural setting:
Estimate SBP (LCD blinded) for 6 hours at start of cuff inflation















CHAPTER 4
RESULTS

The primary purpose of this study was to determine if hypertensive persons could

learn to estimate their SBP using a BP feedback and biosituational self-awareness

training intervention. This was determined by comparing the accuracy of the SBP

estimation before and after training. The secondary purpose of this research was to

compare the differences in the mean improvement of actual to estimated SBP between

different groups of hypertensives within the sample. These groups include college-

educated (CE) hypertensives compared to non-CE (NCE) hypertensives, hypertensives

with a body mass index (BMI) < 30 compared to hypertensives with a BMI > 30, male

hypertensives compared to female hypertensives, hypertensives less than 48 years of age

compared to hypertensives > 48 years of age, and hypertensive medication (HM) users

compared to hypertensive medication (HM) nonusers.

This chapter will first present descriptive statistics, including means, standard

deviations, and frequency distributions for each variable. The hypotheses posed in

Chapter 1 will be addressed using paired samples t-tests and independent samples t-tests.

For all results, data will be expressed as means + standard deviations and/or percentages.

Descriptive Results

Sample Characteristics

Over 60 potential subjects were screened for inclusion in this study. However,

only 42 subjects met the final inclusion criteria. Of these 42 subjects, 3 subjects were









excluded from the analysis for different reasons. One male subject was excluded after

completion of day 1 because his BP on day 1 was low. This subject had a mean SBP on

day one of 101 mmHg and a minimum BP of 74/52. The subject reported symptoms of

"not feeling well" and was being treated for chronic hypothyroidism. It was

recommended that the subject seek care from his healthcare provider and withdraw from

the study. A female subject was excluded from the study after day 1 because her BP

levels were excessively high. Her mean SBP level was 192 mmHg and her maximum BP

was 201/116. She was advised to obtain immediate medical care. She contacted her

physician, obtained medical treatment, and was released from the study. A third subject

withdrew from the study after day 1 because of difficulties that she had in performing the

protocol activities during her normal work/home day.

A total of 39 subjects completed the study protocol. Of the total, 15 subjects were

male and 24 subjects were female. The male group ranged from 26 to 65 years with a

mean age of 45.1 years. The female group ranged from 21 to 65 years, with a mean age

of 50.4 years.

Subject demographics expressed in numbers and percentages were gender, race,

age, marital status, family history of hypertension, veteran status, time with diagnosis,

education level, hypertension medication type, overall medication type, and habits of

cigarette smoking, alcohol use, caffeine use, and exercise. Table 4-1 shows the subject

demographics for the total hypertensive sample (N = 39), NCE subjects (N = 15), and CE

subjects (N = 24). Table 4-2 compares the lifestyle variables for the total hypertensive

sample, NCE subjects, and CE subjects. Table 4-3 compares the health status data of the

total sample of hypertensives, NCE subjects, and CE subjects.









Table 4-1. Comparison of demographic data for the total sample, college-educated
subjects, and noncollege-educated subjects


Gender
Male
Female
Race
Caucasian
African American
Age
30 and under
31-40 years
41-50 years
51-60 years
61-65 years
Martial Status
Married
Never married
Widowed
Divorced
Education Level
HS graduate
Some college/tech.
College graduate
Graduate school
VA/Veteran Affiliate
No
Yes


Total sample
(N = 39)
N (%)


15 (38.5)
24(61.5)

32(82.1)
7(17.9)

4(10.3)
5(12.8)
12 (30.8)
13 (33.3)
5(12.8)

27 (69.2)
3 (7.7)
2 (5.1)
7(17.9)

8 (20.5)
16(41.0)
6(15.4)
9(23.1)

22 (56.4)
17 (43.6)


Noncollege-
educated subjects
(N = 24)
N (%)

9 (37.5)
15 (62.5)

18(75.0)
6 (25.0)

1 (4.2)
2 (8.3)
6 (25.0)
12 (50.0)
3 (12.5)

16 (66.7)
2 (8.3)
2 (8.3)
4(16.7)

8 (33.3)
16 (66.7)
0 (0.0)
0 (0.0)

18(75.0)
6 (25.0)


College-educated
subjects
(N= 15)
N (%)

6(40)
9(60)

14 (93.3)
1 (6.7)

3 (20.5)
3 (20.5)
5 (33.3)
2(13.3)
2(13.3)

11(73.3)
1 (6.7)
0 (0.0)
3 (20.0)

0 (0.0)
0 (0.0)
6 (40.0)
9 (60.0)

4 (26.7)
11 (73.3)


Table 4-2. Comparison of lifestyle data for the total sample, college-educated subjects,
and noncollege-educated hypertensive subjects


Total sample
(N = 39)
N (%)


Noncollege-
educated subjects
(N = 24)
N (%)


College-educated
subjects
(N= 15)
N (%)


Current Tobacco Use
No
Yes
Regular Alcohol Use
No
Yes
Regular Caffeine Use
No
Yes
Regular Exercise
No
Yes


30 (76.9)
9(23.1)

18(46.2)
21 (53.8)

5 (12.8)
34 (87.2)

15 (38.5)
24(61.5)


18(75.0)
6 (25.0)

13 (54.2)
11 (45.8)

5 (20.8)
19(79.2)

10(41.7)
14(58.3)


12 (80.0)
3 (20.0)

5 (33.3)
10 (66.7)

0 (0.0)
15(100.0)

5 (33.3)
10 (66.7)









Table 4-3. Comparison of health status data for the total sample, college-educated
hypertensive subjects, and noncollege-educated hypertensive subjects.

Noncollege- College-educated
Total sample educated subjects subjects
(N = 39) (N = 24) (N = 15)
N(%) N(%) N(%)
Time with diagnosis of hypertension
Less than 5 years 27 (69.2) 14 (58.4) 13 (86.7)
5-10 years 6(15.4) 6(25.0) 0(00.0)
11-20 years 4(10.3) 2 (8.3) 2(13.3)
21 or more years 2 (5.1) 2 (8.3) 0 (0.0)
Family history of cardiovascular disease
No family history 2 (5.1) 0 (0.0) 2(13.3)
1 FH item selected 4 (10.3) 2 (8.4) 2 (13.3)
2 FH item selected 9 (23.1) 6 (25.0) 3 (20.0)
3 FH item selected 6 (15.4) 3 (12.5) 3 (20.0)
4 FH item selected 10 (25.6) 5 (20.8) 5 (33.4)
5 FH item selected 8 (20.5) 8 (33.3)* 0 (0.0)*
Hypertension medication type
Not taking HTN meds 16 (41.0) 9 (37.5) 7 (46.7)
Ace inhibitor only 8(20.5) 4(16.7) 4(26.7)
Calcium channel blocker only 3 (7.7) 3 (12.5) 0 (0.0)
Beta blocker only 2 (5.1) 0 (0.0) 2(13.3)
Diuretic Only 2 (5.1) 2 (8.3) 0 (0.0)
Other HTN med only 1 (2.6) 1 (4.2) 0 (0.0)
2 or more HTN meds 7(18.0) 5(20.8) 2(13.3)
Overall medication type
Not taking medications 6 (15.4) 3 (12.5) 3 (20.0)
Taking HTN meds only 10(25.6) 4(16.7) 6(40.0)
Taking other type of meds only 10 (25.6) 6 (25.0) 4 (26.7)
Taking other med and HTN 13 (33.4) 11 (45.8)* 2 (13.3)*
med
* indicates p 0.05 by Mann-Whitney-U Nonparametric Tests.

Clinical Characteristics

The clinical characteristics of the subjects, including age, weight, height, BMI,

actual and estimated SBP day 1, actual and estimated SBP day 2 and 3, actual and

estimated SBP day 4, mean absolute differences of actual SBP (ASBP) minus estimated

SBP (ESBP) for each day, and number of observations are expressed using means and

standard deviations and are presented in Table 4-4. The mean scores for each study day

and across all study days are summarized in Table 4-4. The mean ASBP measurements










were similar among the total sample on days 1 and the average of days 2 and 3; 137.0 +

11.0 mmHg and 136.1 + 15.3 mmHg, respectively. On day 4, the mean ASBP was

slightly lower at 136.1 + 12.1 mmHg, but this reduction was not statistically significant.

Among the 39 subjects, there were 485 BP measurements/estimations on day 1, 880 BP

measurements/estimations on day 2 and 3, and 482 BP measurements/estimations on day

4. In total, there were 1847 BP measurements/estimations among the 39 subjects for the

total 4-day study period.

Table 4-4. Clinical characteristics for the total sample (N = 39)

Total Sample (N = 39)
Initial screening Day 1 Day 2 & 3 Day 4
Age (yrs.) 48.4 + 11.5
Weight (lbs.) 194.1 + 46.3
Height (in.) 66.7 + 4.6
BMI (kg/m2) 30.5 + 5.4
Actual SBP (mmHg) 137.0 + 11.0 137.1 + 9.27 136.1 + 12.1
Mean Actual SBP Range (mmHg) 51 36 52
Min ASBP (mmHg) 94 91 99
Max ASBP (mmHg) 176 192 174
Estimated SBP (mmHg) 137.3 + 8.6 136.0 + 5.49 136.1 + 11.8
Absolute difference ASBP-ESBP (mmHg) 10.1 + 3.5 7.5 + 5.70 9.3 + 3.2
Number ofASBP-ESBP observations 12.4 + 2.3 20.9 + 6.9 12.3 + 1.7

Analytic Results for Hypotheses

Procedure for Calculating Mean Scores

As described previously, the study protocol involved 4 days of BP measurement,

at a frequency of every 30 minutes for 6-hours each day. Therefore, theoretically each

subject should have 12 observations or BP measurements/estimations per day. However,

on Day 1, the number of BP observations for each subject ranged from 9 to 20

observations, with a mean number of observations at 12.4. Likewise, on day 4 the

number of BP observations for each subject ranged from 9 to 15 observations with a

mean of 12.3 observations. This variation occurred for a number of reasons. First, some









subjects correctly had their BP taken 12 times but the BP measurement was deleted due

to an error. The error may have been caused by improper inflation/position of the cuff,

too much activity of the arm or body during cuff inflation, and/or the BP reading was

higher than the previous BP reading and the cuff did not inflate to an adequate level to

obtain the reading. Secondly, a few subjects did not follow instructions completely and

performed either too few (9 to 11) readings or too many (13 to 20) readings. The

majority of subjects performed the tasks as directed and performed 12 readings. Data

were included if there were at least 9 observations per day. All 39 subjects had at least 9

observations per day. To assure that the mean score reflected the variation in number of

observations per day, each individual subject's scores were analyzed separately to

compute a mean actual SBP, mean estimated SBP, and a mean absolute difference

between actual and estimated SBP for each subject.

Absolute difference. The absolute difference (AD) is defined as the absolute

value of the mean difference. Without using absolute difference, overestimates and

underestimates would average to a smaller mean difference. The absolute difference has

been calculated for day 1 (mean actual SBP minus estimated SBP day 1), day 2 and 3

(mean actual SBP minus estimated SBP day 2 and 3 combined), and day 4 (mean actual

SBP minus estimated SBP day 4).

Mean improvement. The mean improvement is defined as the absolute value of

the mean difference of day 1 (mean actual SBP minus mean estimated SBP) minus the

absolute value of the mean difference of day 4 (mean difference of actual SBP minus

estimated SBP). The mean improvement represents a measure of improvement in SBP

estimation between day 1 and day 4.










The Paired Sample t-Test

The paired sample t-test was used to compare the means of two scores from

related samples. The assumptions of a paired t-test are that the variables are at interval or

ratio levels and that they should be normally distributed. Figure 4-1 depicts the

improvement scores of the entire sample of adult hypertensives. It illustrates a relatively

normal distribution of improvement scores. Because of the robustness of a t-test, it is

appropriate to use a paired t-test for these data.

The Independent Samples t-Test

The independent samples t-test compares the means of two independent groups.

The assumptions of this test are that the two groups are independent of each other, the

dependent variable must be measured on an interval or ratio level, and the scores should

be normally distributed. All assumptions have been met for this test (refer to Figure 4-1)

for distribution of mean improvement scores.

12

10
Clo



E 4

Z Std. Dev = 4.41
Mean = .8
0 N=39.00
-8.0 -4.0 0.0 4.0 8.0 12.0
-6.0 -2.0 2.0 6.0 10.0

AD Day 1 Minus AD day 4

Figure 4-1. Distribution of mean improvement scores for total sample (N = 39). Mean
and standard deviation of the improvement in SBP estimation for the entire
sample of hypertensive persons is provided.









The mean actual SBP and estimated SBP across all study days was 136.5 and

136.1 mmHg, respectively. The mean difference across all study days was + 0.43

mmHg. This finding suggests that subjects were extremely accurate in estimating their

SBP; however, the mean difference does not take into account the variability of SBP

measurement/estimations and the over- and underestimators of SBP. The absolute value

of the difference between estimated and actual SBP for each subject was calculated and

averaged and was found to be 8.6 mmHg. Therefore, subjects were actually estimating

on average within + 8.6 mmHg of their actual SBP level across all study days. The AD

was calculated and used in this study to take into consideration that there would be over-

and underestimations of SBP and to gain the true picture of SBP elimination. This

method has been used by Luborsky et al. (1976) in a similar BP estimation study.

Hypotheses

Hypothesis 1. Adult hypertensives differ significantly in their mean AD after the
ambulatory BP awareness training intervention, compared with before the
training intervention.

For hypothesis 1, the mean absolute difference of day 1 was compared to the

mean absolute difference of day 4, using a paired-samples t-test. The mean absolute

difference on day 1 (pretraining) was 10.1 + 3.5 mmHg and the mean absolute difference

on day 4 (posttraining) was 9.29 3.2 mmHg. The hypertensive subjects improved their

mean scores after the training, however the improvement was not statistically significant

(t = 1.094, df = 38, p = 0.281). Of the 39 subjects, 18 subjects showed no improvement

and 21 subjects (54%) showed improvement in estimating their SBP after the training.

See Figure 4-1 for a graphical display of the AD of day 1 minus the AD of day 4 (mean

improvement) of the total hypertensive sample. As Figure 4-1 shows, the mean

improvement was 0.8 4.4 mmHg for the total sample of hypertensive subjects (N = 39).









Hypothesis 2. College-educated hypertensives differ significantly from noncollege-
educated hypertensives in their mean improvement of SBP estimation.

For hypothesis 2, CE hypertensives were compared to NCE hypertensives to

assess differences in their mean improvement scores for day 1 and day 4. The CE

subgroup was composed of 15 subjects (6 males, 9 females), mean age 43.2 13.7, mean

BMI = 29.02, and mean improvement 2.0 + 4.1 mmHg. The NCE subgroup was

composed of 24 subjects (9 males, 15 females), mean improvement 0.04 4.5 mmHg,

mean age 51.6 years, mean BMI 31.4. The CE and NCE groups had similar marital

status and frequencies of reported tobacco, caffeine, and alcohol use. Compared to CE

subjects, NCE subjects were older (p = 0.05), more frequently taking medications for

hypertension (p = 0.05), and had more family cardiovascular disease history (p = 0.05).

In addition, trends in NCE subjects included a longer personal history of hypertension,

less alcohol use, and had a greater African American racial percentage; however, these

were not statistically significant compared with CE subjects. The mean actual SBP for

the CE group was significantly lower compared to the NCE group on day 1; 132.8 mmHg

and 139.6 mmHg respectively (p = 0.05). Similarly, the mean SBP on day 4 was lower

for the CE group, however not significantly (p = 0.108). Refer to Tables 4-1, 4-2, 4-3,

and 4-5 for demographic, health status, lifestyle factors, and clinical data for these

groups.

To test hypothesis 2, an independent samples t-test was used. The difference

between the two groups was not statistically significant (t = -1.333, df= 37, p = 0.19).

The mean improvement scores of NCE hypertensives (mean improvement 0.04 4.5

mmHg) were not significantly different than the mean improvement of CE hypertensives

(mean improvement = 2.0 + 4.1 mmHg). Because the analysis performed in hypothesis 2









is comparing the two independent groups improvement using an independent samples

t-test, it is unclear if the college-educated group alone improved significantly between

day 1 and day 4. Therefore, a paired-samples t-test was performed to assess the change

in mean AD from day 1 to day 4 among the CE subjects.

Hypothesis 3. College-educated hypertensives decrease their mean AD post-training
compared to pretraining.

A paired samples t-test was calculated to compare the pretraining mean AD to the

posttraining mean AD among CE hypertensives. The mean AD on day 1 was 9.74 3.4

mmHg and the mean AD on day 4 was 7.78 2.0 mmHg. A significant decrease in

mean AD from pretraining to posttraining was found using a one-tailed test (t = 1.86, df

=14, p = 0.04). This supports the hypothesis that CE hypertensives improve their

accuracy significantly after training. Refer to Tables 4-1, 4-2, and 4-3 for a description

of the demographic, health status, and lifestyle factors data of the CE subjects. Refer to

Table 4-5 for a description of the clinical characteristics of the group of CE

hypertensives, expressed using means and standard deviations.

An independent samples t-test was calculated to compare the mean improvement

scores of female CE hypertensives compared to mean improvement scores of male CE

hypertensives. The mean improvement scores for female CE hypertensives (N = 9) was

3.31 4.76 mmHg. The mean improvement for male CE hypertensives was -0.093

1.17 mmHg. This difference between groups approached, but did not reach statistical

significance (p = 0.069). As shown in Figure 4-2, male CE hypertensives actually

worsened their ability to estimate their SBP after the training, while the female CE

hypertensives improved at near statistically significant levels (p = 0.069).












Table 4-5. Clinical characteristics of college-educated hypertensives (N = 15).


College-educated hypertensives
(N= 15)


Age (yrs.)
Weight (lbs.)
Height (in.)
BMI (kg/m2)
Actual SBP (mmHg)
Estimated SBP
(mmHg)
Absolute difference
ASBP-ESBP
(mmHg)
Number of ASBP-
ESBP Observations


Initial
screening
*43.2 13.7
191.0 47.9
67.7 4.2
29.0 5.0


Day 1


*132.8 + 10.3
135.9 7.8


9.7 3.4


12.8 + 2.9


Day 4


Noncollege-educated hypertensives
(N = 24)
Initial
rnin Day 1 Day 4
screening
*51.6 8.8
196.0 + 46.2
66.1 4.8
31.4 5.6


132.1 + 11.3
132.7 + 10.6


7.8 + 2.0*


13.1 1.6


*139.6 + 10.8
138.1 + 9.2


10.3 + 3.7


12.2 1.7


138.5 + 12.1
138.2 + 12.2


10.2 3.5


11.8 1.6


Values are expressed as means standard deviations.
* p < 0.05 versus pretest scores by paired t-test within groups or independent samples t-tests between groups.










12 i

-10

I8 35

6
.E Today 1
S4 Mday4
2

0
male female
Figure 4-2. Gender effects on estimation of SBP among college-educated hypertensives
(N= 15).

Hypothesis 4. Hypertensives with a BMI <30 differ significantly than hypertensives with
a BMI > 30 in their mean improvement.

To test the hypothesis that hypertensives with a BMI < 30 differ significantly than

hypertensives with a BMI > 30 in their mean improvement, an independent samples t-test

was used. The BMI < 30 group was composed of 17 subjects; 3 males and 14 females.

The BMI > 30 group was composed of 22 subjects; 12 males and 10 females. Compared

to BMI < 30 group, subjects with BMI > 30 had significantly more males (p = 0.02),

asthma (p = 0.05) and showed trends toward more chronic pain history (p = 0.06) and

less exercise (p = 0.09). The mean actual SBP for the BMI < 30 group (N= 17) was

greater than the mean actual SBP of the BMI > 30 group of subjects; however this

difference was not statistically significant. The BMI < 30 groups' mean actual SBP was

139.5 on day 1 and 138.2 on day 4. The BMI > 30 group had a mean actual SBP of

135.1 mmHg on day 1 and 134.5 mmHg on day 4.

An independent samples t-test was calculated to compare the mean improvement

score of the BMI < 30 subgroup with the mean improvement score of the BMI > 30







83

subgroup. The mean improvement score of the BMI < 30 subgroup was .9 + 3.9 mmHg

and the mean improvement score for the BMI > 30 subgroup was .7 4.9 mmHg. The

mean improvement scores of the BMI < 30 group were not statistically different than the

mean improvement scores of the BMI > 30 group (t = -.158, df= 37, p = .875).

Figure 4-3 shows the effects of BMI level on estimation of SBP as measured by absolute

differences of actual and estimated SBP for days 1 and 4. As shown in Figure 4-3, both

subgroups of BMI had decreases in their mean AD between day 1 and day 4; however,

these trends were not statistically significant.


12
11 10.65
M 10 9.7 9.64
cmr 10 f
8.96
9





5

4
3
BMI less than 30 BMI greater than 30

Figure 4-3. BMI Effects on Estimation of SBP in Total Sample (N = 39).

Hypothesis 5. Male hypertensives differ significantly in their mean improvement,
compared with female hypertensives.

To test the hypothesis that male hypertensives differ significantly in their mean

improvement, compared with female hypertensives, an independent samples t-test was

performed. There were 15 male subjects and 24 female subjects. Comparing both

groups, male mean age was 45.1 years versus 50.4 years (p = 0.17) and mean BMI was







84

32.3 versus 29.3 (p = 0.06). The groups differed significantly in terms of medication use

(p = 0.02) and medication type (p = 0.01). Among females, 96% reported taking one

medication on a daily basis compared with 67% males. Seventy percent of females

reported taking antihypertension medications, whereas only 40% of males reported

taking hypertension medications. Mean BMI for males was higher than females (32.3

kg/m2 versus 29.3 kg/m2 respectively) (p = 0.07). Actual SBP levels for days 1 and 4

were not significantly different between males compared to females. Interestingly,

female subjects mean actual SBP decreased from 136.6 mmHg on day 1 to 134.8 mmHg

on day 4. The mean actual SBP was also lower for the females compared with the males.

Additionally, the males' mean actual SBP increased between days 1 and 4, while the

females' mean actual SBP decreased. These trends in mean SBP were not found to be

statistically significant.

An independent t-test was calculated comparing the mean improvement scores of

male hypertensive subjects to female hypertensive subjects. No significant differences

were found (t = -.752, df = 37, p = .457). The mean improvement of the male

hypertensives (0.1 + 4.4 mmHg) was not significantly different than the mean

improvement of the female hypertensives (1.2 4.5 mmHg). Figure 4-4 shows the

effects of gender on estimation of SBP among the total sample of hypertensive subjects

(N = 39).

Hypothesis 6. Hypertensives < 48 years of age differ significantly compared to
hypertensives > 48 years and older.

To test the hypothesis that hypertensives < 48 years of age differ significantly

compared to hypertensives > 48 years and older, an independent samples t-test was

performed. The < 48 years of age group was composed of 24 subjects (8 males and 16









females). The > 48 years of age group was composed of 15 subjects (7 males and 8

females). Both groups were similar for all demographic variables except education level

(p = 0.03). Sixty percent of younger subjects were college-educated compared with 25%

for the older group. The mean actual SBP for the < 48 years of age group was 130.8

mmHg for day 1 and 131.3 mmHg for day 4. The mean actual SBP for the > 48 years of

age group was 140.9 mmHg for day 1 and 139.0 mmHg for day 4. The < 48 years of age

group had significantly lower actual SBP than the > 48 years of age group on days 1 and

4 (p = 0.004 and p = 0.05 respectively by independent samples t-test).

11

10.5
0)
C 10

-- Male
a 9.5 5
-- Female

S 9 9

8.5

8
Day 1 Day 4

Figure 4-4. Gender Effect on Estimation of SBP in Total Sample (N = 39).

An independent samples t-test was calculated comparing the mean improvement

of hypertensives less than 48 years of age to hypertensives aged 48 years and older. The

mean improvement of hypertensives less than 48 years of age (0.9 2.9 mmHg) was not

significantly different than the mean improvement of hypertensives 48 years of age and

older (0.71 5.2 mmHg). No significant difference was found (t = .117, df = 37, p =

.907). Refer to Figure 4-5 for graphical presentation of these results.











12 10.9
10.2

8.7
9
S7.9

Day 1
a 6
*Day 4


3


0
Age less than 48 Age greater or equal 48
Figure 4-5. Age and Estimation of SBP in Total Sample (N = 39).

Hypothesis 7. Hypertensives using antihypertension medication differ significantly in
their mean improvement compared with hypertensives not taking
medications.

To test the hypothesis that hypertensives using antihypertension medication differ

significantly in their mean improvement compared with hypertensives not taking

medications, an independent samples t-test was performed. The HM nonuser and HM

user subjects were similar in age, marital status, and education level. The HM nonuser

subjects trended to be more overweight, had the diagnosis of hypertension longer, and

had higher actual and estimated SBP compared with the HM users; however, these trends

were not significant. The HM users mean SBP on days 1 and 4 were similar to the HM

nonusers; with a mean actual SBP of 136.5 for HM users and 137.7 for HM nonusers for

both days. Refer to Table 4-6 for a description of the HM users and nonusers. Values

are expressed as means + standard deviations, frequencies, and percentages.

An independent samples t-test was calculated comparing the mean improvement

of hypertensives using HM (N = 23) to hypertensives not using medication (N = 16). A

significant difference was found between groups (t = 2.038, df = 37, p = 0.05) for a two-







87

tailed test (p < 0.05). Figure 4-6 compares the mean improvement between both groups.

The mean improvement of the HM nonuser group (2.4 5.2 mmHg) was significantly

better than the group using HM (-.4 + 3.4 mmHg).

Table 4-6. Description of antihypertension medication user and nonusers


Age
Gender
Education level
Noncollege educated
College-educated
Race
Caucasian
African American
Time with diagnosis
Less than 5 years
5-10 years
11-20 years
21 or more years
BMI
ASBP day 1, mmHg
ESBP day 1, mmHg
ASBP day 4, mmHg
ESBP day 4, mmHg
AD day 1, mmHg
AD day 4, mmHg
Mean improvement, mmHg
Number of observations day 1
Number of observations day 4
* p<0.05


HM user
(N = 23)
49.2 + 10.7
6 males, 17 females

15 (65.2%)
8 (34.8%)

18(78.3%)
5(21.7%)


14 (60.9%)
3 (13.0%)
4 (17.4%)
2 (8.7%)
29.6 + 5.5
136.4 + 12.0
135.6 9.5
135.1 13.5
135.1 + 14.0
9.7 3.3
10.1 + 3.1
-.4 + 3.4
12.0 + 1.8
12.5 + 1.7


HM nonuser
(N= 16)
47.2 + 12.8
9 males, 7 females

9 (56.2%)
7 (43.8%)

14 (87.5%)
2 (12.5%)


13 (81.3%)
3 (18.8%)
0 (0.0%)
0 (0.0%)
31.8 5.3
137.9 9.6
139.7 6.9
137.5 + 10.0
137.4 7.9
10.5 3.8
8.1 + 3.0*
2.4 5.2*
13.0 2.8
12.0 + 1.8


As shown in Figure 4-7, gender has an effect on estimation of SBP among

subjects who are not taking HM (N =16). Female hypertensives that didn't take

medications for hypertension (N = 7) were compared to male hypertensives that didn't

take medications for hypertension (N = 9) using an independent samples t-test. A

significant difference (p = 0.03) was found between the two groups using a two-tailed









test. The mean improvement for hypertensives that did not take HM was 0.06 +

5.4 mmHg for males and 5.5 3.1 mmHg for females. This improvement is also

interesting given the fact that similar findings occurred when comparing CE males and

females. Refer to Table 4-7 for a description of hypotheses and major findings.


3

2.5

2

1.5

1

0.5

0

-0.5

-1


Figure 4-6.


SImprovement


HM Non-Users (N = 16) and HM User (N = 23)

Comparison of improvement in SBP estimation between HM nonusers
and HM users. *p< 0.05 by independent sample t-test.

-I 12.88 I


8.72 8.65


* Day 1
* Day 4


Male Female

Figure 4-7. Gender effects on estimation of SBP among HM nonusers (N = 16).
Female scores statistically different than male scores at p < 0.05 level by
independent sampled t-test.


HMM r Jon-userS


-o0











Table 4-7. Summary of major outcome measures for each hypothesis


Hypothesis Focus
H1 TS (N = 39)


CE (N 15)
& NCE
(N 24)
CE (N 15)


Outcome
measure
Day 1 mean
AD compared
with day 4
mean AD


Compare both
groups mean
improvement
Day 1 mean
AD compared
with Day 4
mean AD


Analysis
method
Paired-samples
t-test




Independent
samples t-test

Paired-samples
t-test


Re sults
Mean AD D1 10.1
mmHg
Mean AD D4 9.3
mmHg
MI 0.8 mmHg

MI CE = 2.0 mmHg
MINCE = 0.04 mmHg

Mean AD D1 9.74
mmHg
Mean AD D4 7.8
mmHg
MI 2.0 mmHg
*p = 0.042


H4 BMI < 30 Compare both Independent MI BMI< 30 0.9 mmHg
(N 17) & groups mean samples t-test
BMI> 30 improvement MI BMI> 30 0.7 mmHg
(N 22)
H5 Males (15) & Compare both Independent MI males 0.1 mmHg
females (24) groups mean samples t-test MI females 1.2 mmHg
improvement
H6 Age < 48 Compare both Independent MI age < 48 0.9 mmHg
(N 15) & groups mean samples t-test MI age > 48 0.7 mmHg
Age > 48 improvement
(N 24)
H7 HM nonuser Compare both Independent MI HM nonuser 2.43
(N = 16) & groups mean samples t-test mmHg
HM user improvement MI HM user -0.4 mmHg
(N 13) p = 0.05
* Note: TS =total sample, CE = college educated, NCE = noncollege-educated, MI=
mean improvement, HM = hypertension medication, BMI = body mass index.

Analysis of Covariance

It is useful to determine if there are any covarying factors that are significantly

related to mean improvement of estimating SBP. A one-way between subjects

ANCOVA (analysis of covariance) allows the investigator to remove the effect of a

known covariate, thereby providing a method of statistical control. An ANCOVA was

performed to examine the effects of gender and hypertension medication use on the total









sample mean improvement scores, covarying out the effects of BMI and age. The

corrected model was significantly related to mean improvement in estimation of SBP

between days 1 and 4 (p = 0.05). The main effect of hypertension medication use was

significantly related to mean improvement (p = 0.05), with nonusers of hypertension

medication having greater improvement (2.4 + 5.2 mmHg) than users of hypertension

medication (-.4 + 3.4 mmHg). The interaction between hypertension medication use and

gender was also significantly related to mean improvement (p = 0.03). These effects

were seen after taking into account BMI and age. Both BMI (p = 0.5) and age (p = 0.9)

were not significantly related to mean improvement scores.

Reporting Symptoms and Estimating SBP

Among the total hypertensive sample, 14 (36%) participants reported symptoms

associated with high BP. Reported symptoms included tenseness, flushing, and

headache. A greater improvement (1.14 4.9 mmHg) was seen in the 14 subjects who

reported symptoms associated with elevated BP compared to the 25 subjects who did not

report symptoms (0.6 + 3.5 mmHg). An independent samples t-test was performed to

compare the mean improvement scores of subjects who reported experiencing symptoms

with those who did not. No significant differences were found (t = -.38, df= 37, p =

0.71). Refer to Figure 4-8 for a description of this data.

Among hypertensives that do not take HM, 13 subjects reported not experiencing

symptoms relating to their high BP levels and 3 reported experiencing symptoms relating

to their high BP levels. The mean improvement of those subjects is shown in Figure 4-9.

The mean improvement of subjects who did not take HM and reported symptoms

associated with high BP levels (N=3) improved an average of 4.14 mmHg after training.

Subjects who did not report symptoms associated with their SBP and who were not using







91

HMs (N = 13) improved an average of 2.03 mmHg after training. The small numbers of

participants in each group and the uneven distribution of subjects per group make this

comparison difficult and more inquiry is needed.

11
~10
2 9
8
7
Day 1
o6 6 EDay 4
S5
4
3
No Yes

Figure 4-8. Reporting of symptoms associated with high BP and SBP estimation.

N=16
4.5 .4 14
4 -
E 3.5 -
3
2 2.5 u
E 2- yes
C 1.5
c 1
S0.5
0
Mean Improvement
Figure 4-9. Reporting of symptoms among nonusers of HM (N = 16).

High BP Estimation

Because of the repeated measures design of the study, absolute differences can be

computed for repeated measures of actual SBP and estimated SBP. A total of 1847 BP

measurements/estimations were analyzed. Using SPSS, a filter variable was created by

selecting only cases that were less than 140 mmHg (N = 1095). The mean AD across all







92

days was compared between cases that were < 140 mmHg compared with cases that were

S140 mmHg. There were statistically significant differences between the two groups

using an independent samples t-test (t = 4.13, df = 1845, p = 0.001). The mean AD

across all days for the > 140 mmHg group of cases was 9.37 + 7.4 and the mean AD

across all days for the < 140 mmHg group of cases was 8.0 + 6.7 mmHg. The less than

140 mmHg group of cases (N = 1095) had a mean AD on days 1, 2, and 3, and 4 of 9.9

mmHg, 6.6 mmHg, and 8.8 mmHg, respectively. The greater than or equal to 140

mmHg group of cases (N = 752) had a mean AD on days 1, 2, and 3, and 4 of 10.0

mmHg, 8.7 mmHg, and 9.9 mmHg, respectively.















CHAPTER 5
DISCUSSION AND RECOMMENDATIONS

All descriptive and analytic results that addressed each research hypothesis will

be discussed in this chapter. Conclusions and implications for clinical practice as well as

recommendations for future research will also be provided.

Discussion of Results

This study was unique in its design and attempts to directly focus on

hypertensives and provide both physiological and self-awareness feedback, especially

using a repeated measures design and ambulatory BP monitoring. Similar studies have

undertaken the task of determining the effects of feedback on BP estimation (Barr et al.,

1988; Cinciripini et al., 1979; Greenstadt et al., 1988; Luborsky et al., 1976). However,

the present study is the first to examine the effects ofbiosituational feedback using

ambulatory monitoring on the estimation of SBP in adult hypertensive persons. Prior

studies were composed ofnormotensive, younger, male samples. In addition, this study

sought to uncover differences in estimation of SBP among a population of adult

hypertensives and also between different sub-groups of the sample.

Hypothesis 1

For hypothesis 1, hypertensive subjects' day 1 mean absolute difference between

actual and estimated SBP was compared to their day 4 mean absolute difference using a

paired-samples t-test. The mean absolute difference on day 1 was 10.1 mmHg. The

mean absolute difference on day 4 was 9.3 mmHg. These findings indicate that subjects