Predictors of adherence to exercise after heart transplantation.

MISSING IMAGE

Material Information

Title:
Predictors of adherence to exercise after heart transplantation.
Alternate title:
Adherence to exercise after heart transplantation
Physical Description:
xi, 177 leaves : ; 29 cm.
Language:
English
Creator:
Plitnick, Katherine Rose, 1960-
Publication Date:

Subjects

Subjects / Keywords:
Heart Transplantation -- rehabilitation   ( mesh )
Exercise -- Adult   ( mesh )
Exercise Therapy   ( mesh )
Health Behavior -- Adult   ( mesh )
Self Efficacy -- Adult   ( mesh )
Patient Compliance -- Adult   ( mesh )
Genre:
bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

Notes

Thesis:
Thesis (Ph. D.)--University of Florida, 2002.
Bibliography:
Includes bibliographical references (leaves 161-176).
Statement of Responsibility:
by Katherine Rose Plitnick.
General Note:
Typescript.
General Note:
Vita.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
oclc - 52306135
ocm52306135
System ID:
AA00011227:00001

Full Text











PREDICTORS OF ADHERENCE TO EXERCISE
AFTER HEART TRANSPLANTATION













By

KATHERINE ROSE PLITNICK


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
























Copyright 2002


by


Katherine Rose Plitnick














ACKNOWLEDGMENTS

I would like to acknowledge and thank first and foremost Dr. Jean E. Davis, PhD,

RN, for her expert guidance, support and positive attitude in assisting me to the

completion of this dissertation at the University of Florida. Special thanks also go to my

committee members-Jim Jessup, PhD, RN; Hossein Yarandi, PhD; Randy Braith, PhD;

and Sam Sears, PhD-for their guidance on this dissertation and sharing of knowledge in

the classroom. To friends and family who were there from the beginning to the end, I

thank them for listening and caring.















TABLE OF CONTENTS

Page
ACKNOWLEDGMENTS ...................................... ...... iii

LIST OF TABLES ................................................ vii

LIST OF FIGURES ................ .......................... .. ix

ABSTRACT ............... .. ............................. x

CHAPTER

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

Stages of Heart Transplantation .............................. ..... 3
Exercise in Heart Transplant Patients .................. .............. 5
Exercise Adherence ................................................ 8
Problem Statement ................... ......... ........... 10
Statement of the Purpose ........................... ............... 11
Research Questions ....................................... 11
Significance of the Study .. ...................... .. .... ....... 12
Summary ................. ..... ................... ........ 14

2 REVIEW OF LITERATURE .................. ................ 16

Theoretical Fram work .. ..................... ............... 16
Review of Literature .. ........... .......... .................... 21
Attitude Toward the Behavior ................... ................... 21
Subjective Norm ............... ... ....................... 25
Perceived Behavioral Control .................................... 26
Summary ............... .................................. 50

3 METHODOLOGY ........... ................................... 51

Research Design ....................... ...................... 551
Human Subjects Protection........ ................................ 52
Sample............... .. .................................... 52
Inclusion and Exclusion Criteria. ..................................... 53
Setting........... .............................. ......... 54









Definitions of Major Study Variables .................................. 55
Extraneous Variables .............. ............................. 60
Measurement ................................................... 62
Data Collection Procedure ...................................... .... 75
Data Analysis ............. .................................... 76
Lim stations ................................. ......... .. 77
Summ ary ......................................................... 77

4 RESULTS .................................... ........... 78

Subject Characteristics .................. ................... ...... 78
Summary Data on Exercise ......................................... 79
Summary Data on Major Study Variables .............................. 85
Correlations Among Demographic Variables ............................ 91
Correlations Among Major Study Variables ............................. 93
Research Questions .............................................. 96
Demographic Variables ................... ................... ... 102
Test-Retest Data on Exercise Adherence .............................. 103
Summary ..................... ..................... 107

5 DISCUSSION OF RESULTS ............................ ...... 109

Discussion .......................... ........ ............ 109
Regression Analysis ................... .... ......... ........ 126
Lim stations ............................. ....................... 129
Conclusions ................ ... ........................... 131
Implications ....................... ........................... 133
Summary .............. ......... ................ .......... 135

APPENDIX

A INFORMED CONSENT ........................................ 137

B ADHERENCE TO EXERCISE QUESTIONNAIRE I ..................... 142

C ADHERENCE TO EXERCISE QUESTIONNAIRE II .................... 145

D SELF-MOTIVATION INVENTORY ................................ 151

E ADHERENCE TO EXERCISE QUESTIONNAIRE III ................... 154

F DEMOGRAPHIC DATA SHEET: SAMPLE CHARACTERISTICS ........ 156









G UNIVERSITY OF FLORIDA HUMAN SUBJECTS COMMITTEE
APPROVAL ............................................... 158

H EMORY UNIVERSITY HUMAN INVESTIGATIONS COMMITTEE
APPROVAL .................................... ............ 160

REFERENCES ........................................ ........... 161

BIOGRAPHICAL SKETCH.......................................... 177















LIST OF TABLES

Table page

4-1 Sample Characteristics ............... ................... ........ 80

4-2 Secondary Variables ................................. ......... 81

4-3 Exercise Adherence ...................................... ....... 82

4-4 Type of Exercise, Mean Duration Per Session, Frequency and
Total Time of Exercise Per Week ................................. 83

4-5 Mean Exercise Time ........................................... 83

4-6 Intensity of Exercise .................. .......................... 84

4-7 Psychological Factors .................. ......................... 85

4-8 Social Influence ..................................... ........ 85

4-9 Pre-operative Factors .................. ................... ...... 86

4-10 Pre-operative and Physical Factors .................................. 87

4-11 Situational Factors ..................... ..................... ... 8 89

4-12 Disease-Related Transplant Factors ................................. 90

4-13 Disease-Related Symptom Factors ................................... 91

4-14 Correlations Between Demographics and Exercise Adherence ............. 92

4-15 Correlations Between Psychological Factors, Social Influence,
Situational Factors and Exercise Adherence ......................... 93

4-16 Correlations Between Pre-operative Factors, Physical Factors,
Disease-Related Factors and Exercise Adherence ..................... 95



vii









4-17 Pre-operative Predictors of Exercise Adherence ........................ 97

4-18 Physical Predictors of Exercise Adherence .................. ......... 97

4-19 Psychological Predictors of Exercise Adherence ........................ 98

4-20 Situational Predictors of Exercise Adherence .......................... 100

4-21 Disease-Related Predictors of Exercise Adherence ...................... 101

4-22 Perceived Social Influence Predicting Exercise Adherence ............... 102

4-23 Demographic Predictors of Exercise Adherence ........................ 103

4-24 Test-Retest Data on Adherence to Exercise Questionnaire I ............... 104

4-25 Test-Retest Data on Type of Exercise, Mean Duration Per Session, 105
Frequency and Total Time of Exercise Per Week ......................

4-26 Test-Retest Data on Mean Exercise Time ............................ 106

4-27 Correlations Between Test and Retest Data on Adherence to
Exercise Questionnaire I ................. ...................... 108















LIST OF FIGURES

Figure age

2-1 Theory of Planned Behavior ....................................... 17

2-2 Predictors of Adherence to Exercise After Heart Transplantation
Theoretical Framework ........................................ 20

5-1 Pre-operative Factors Model .................. ................... 113

5-2 Situational Factors Model ...................................... 121

5-3 Predictors of Exercise Adherence ........................... 127














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

PREDICTORS OF ADHERENCE TO EXERCISE AFTER
HEART TRANSPLANTATION

By

Katherine Rose Plitnick

December 2002

Chair: Jean E. Davis
Major Department: Nursing

This non-experimental predictive study identified predictors of adherence to

exercise in heart transplant recipients. The theoretical framework for this study was

based on the Theory of Planned Behavior. Seven research questions were tested to

identify factors that predicted adherence to exercise after heart transplantation. The

factors included pre-operative, physical, psychological, situational, disease-related, and

social influences.

A convenience, non-random sample (N = 16) of subjects who were six months

post-operative heart transplant surgery was obtained. Each subject completed three

questionnaires that assessed their exercise routine, feelings about exercise, symptoms,

and motivation. Also, data were obtained from each subject's medical record. The

results showed positive correlations among pre-operative exercise participation

(r = -0.509, p = 0.043), exercise at home (r = 0.498, p = 0.049), exercising functional

status (r = 0.575, p = 0.019), and exercise adherence. Regression analysis showed that









the pre-operative factors, number of days on the waiting list (F = 6.77, p = 0.032) and

functional status (F = 8.42, p = 0.019), significantly predicted exercise adherence and

accounted for 65% of the total variance. Two situational factors, accessibility (F = 10.37,

p = 0.007) and climate (F = 6.43, p = 0.026), significantly predicted exercise adherence

and together accounted for more than 46% of the total variance. Additional findings

revealed the demographic variable, pre-operative exercise participation (F = 4.90,

p = 0.043), significantly predicted exercise adherence and accounted for over 26% of the

variance.

Implications for clinical practice included increasing the exercise capacity of the

transplant patient in the pre-operative period; developing exercise protocols tailored to

the abilities of the transplant patient both pre-operatively and post-operatively; increasing

the individual's access to exercise; and implementing home-oriented exercise programs.














CHAPTER 1
INTRODUCTION

Heart transplantation is a treatment option for selected patients with end-stage

heart disease. It offers a chance at renewed life and improved quality of life and an

ability to resume normal activities of daily living. According to the seventeenth annual

data report from the Registry of the International Society for Heart and Lung

Transplantation (2001), over 55,000 heart transplants have been performed since 1967.

Dr. Christiaan Barnard performed the first successful human cardiac transplantation in

Cape Town, South Africa. Approximately 2,700 heart transplants are done yearly. The

current one-year survival rate is 85.5%, three-year survival rate is 76.9% and five-year

survival rate is 69.6%. Most heart transplant recipients are male (74%) and white (78%).

The majority of recipients are in the 50-64 age group (50.3%). At the end of June 2001,

there were 4,231 people on the national heart waiting list (United Network for Organ

Sharing--UNOS, July 4, 2001).

Success in heart transplantation is attributed to advances in antimicrobial agents,

immunosuppressive drugs, improved surgical techniques, methods of detecting rejection

and preservation (Forsythe, 1997). For the recipients, the quality of survival is not only

defined by their cardiac function and overall general health but also by their

psychological adaptation during the years after the transplantation.

End-stage heart disease encompasses a wide range of pathophysiologic processes.

The hallmarks are often left ventricular dilatation and severe decreased systolic ejection.









Myocardial failure is the end result (Forsythe, 1997). Once intense therapies and other

surgical options have been tried and tested, the patient is often referred for heart

transplantation. The indications for transplantation include cardiomyopathy, coronary

artery disease, congenital heart disease, valvular heart disease and retransplant or graft

failure (UNOS, 2001). Patients referred for heart transplantation often have a life

expectancy of less than one year. To be considered for transplantation, the following

criteria must be met: New York Heart Association (NYHA) Class III or IV functional

disability that is refractory to maximal medical therapy; inoperable coronary artery

disease with intractable angina symptoms; and intractable malignant ventricular

dysrhythmias unresponsive to therapy. Exclusion criteria for heart transplantation

includes severe pulmonary hypertension with pulmonary vascular resistance greater than

six Woods units; age greater than 65 years; insulin-dependent diabetes with end-organ

damage; weight greater than 140% of ideal body weight; active malignant disease;

irreversible chronic functional impairment of other organs; human immunodeficiency

virus; amyloidosis; substance abuse; and unstable psychosocial status. The patient must

exhibit medical compliance, adequate social support and an appropriate cognitive ability

(Rourke, Droogan, & Ohler, 1999).

The procedure most frequently performed is orthotopic heart transplantation and

involves the donor heart replacing the native heart. The standard or biatrial surgical

technique introduced by Lower and Shumway involves two atrial anastomoses with

connections to the aorta and pulmonary arteries (Dressler, 1999). This traditional

technique, however, alters the size and geometric shape of the atria and has been shown

to be responsible for posttransplant complications such as tachyarrhythmias, tricuspid and









mitral regurgitation, atrial dysfunction and thrombus formation (Aziz, Burgess, El-

Gamel, Campbell, Rahman, Deiraniya, & Yonan, 1999). To preserve the atrial geometry,

two alternative techniques have been developed. The bicaval technique allows complete

excision of the recipient heart and the donor left atrium is anastomosed to a small portion

of the recipient's left atrial cuff. The anastomosis sites are changed to the inferior and

superior vena cavae. This technique has been reported to result in improved cardiac

output and left ventricular performance, decreased right atrial pressure, and a decrease in

the incidence of tricuspid incompetence (Aziz et al., 1999). Furthermore, there is

improved exercise capacity associated with this technique. Total orthotopic

transplantation involves complete atrioventricular transplantation with separate caval and

pulmonary vein anastomoses.

Stages of Heart Transplantation

Heart transplantation does not constitute a single event. It is a process that

involves many stages that individuals must go through and continue throughout their life.

The process started many years earlier during the initial cardiac event that led to end-

stage heart failure. It proceeded through the initial work-up for transplantation to a

waiting period for a donor heart when the individual is placed on the heart transplant

waiting list. With the availability of a suitable donor, the patient must then endure the

surgical procedure and recovery experience. Once discharged from the hospital, the

patient then begins the journey of long-term adjustment to the transplantation. Kuhn,

Davis, and Lippmann (1988) identified seven stages of adjustment for heart transplant

recipients: transplant proposal, evaluation, awaiting a donor organ, perioperative period,

in-hospital convalescence, discharge, and post-discharge adaptation.









In 1999, the median waiting time for heart transplantation was 217 days as

reported by UNOS (2001). In that year, 712 persons died before a suitable donor became

available. One reason for this is the increasing number of patients being placed on the

waiting list and the continued shortage of donor hearts. The waiting period creates many

stressors for the patient and his/her family. Patients face the threat of further physical

deterioration, the fear of dying, and the unpredictability of the availability of a donor

organ. "Uncertainty about whether a donor organ will arrive in time is the primary

concern of patients who need transplantation" (Crone & Wise, 1999, p. 51). Tahan

(1998) identified six factors that affect uncertainty and stress in illness in patients

awaiting heart transplantation: perception of illness-related events; characteristics of the

experienced events; ability to process information; availability of resources and

psychosocial support; ability to recognize and classify the experienced events; and efforts

to reduce uncertainty. Patients undergo a multitude of emotions, behaviors and stressors.

Those who require hospitalization and experience declining health find themselves in a

position of increased dependency and loss of control. Feelings of anger and distrust

surface as they hear of other patients receiving a donor heart (Professional experience,

1991).

When a donor heart becomes available, a chance for renewed health and

improved quality of life becomes a reality. Most patients can anticipate experiencing

renewed strength, energy, and endurance after the surgical recovery period. Quality of

life has been shown to improve in the areas of social interaction, exercise tolerance,

sleep, self-esteem and overall well-being (Crone & Wise, 1999).









However, once the patient survives the surgical experience, the patient may face a

new set of problems after transplantation. The threat of organ rejection, opportunistic

infections, medication-induced side effects, financial strain, frequent medical check-ups

and life-style changes are among some of the stressors that may be encountered after

heart transplantation (Hwang, 1996). One of the life-style changes the patient must

undergo involves physical activity. Research has shown exercise to be a useful and

therapeutic intervention to maximize both exercise tolerance and psychosocial outcomes

in heart transplant recipients (Badenhop, 1995; Kavanagh, 1999; Squires, 1990).

Exercise in Heart Transplant Patients

Physical activity produces major stress on the body and it has the potential to

disrupt internal homeostasis if the body's control systems become overwhelmed. The

control systems that play a major part in maintaining homeostasis during physical activity

are the cardiovascular, respiratory, neuroendocrine, and skeletal muscle systems. Each

system must maintain a steady state by responding and interacting to supply adequate

oxygen and nutrients to the exercising muscles.

Exercise that is planned, structured, and purposeful can have beneficial effects on

the respiratory, cardiovascular, musculoskeletal, and endocrine systems of the body.

Positive psychological effects can also be achieved through regular exercise. Some of the

positive benefits of regular exercise include lower prevalence of cardiovascular risk

factors and reduction in mortality, improved ventilatory efficiency, improved hemostatic

parameters, increased muscle strength and flexibility, enhanced glucose tolerance and

increased sensitivity to insulin, and improved well-being and stress reduction (Shephard

& Balady, 1999).









The heart transplant patient also derives additional benefits from performing

regular exercise. Rest and exercise hemodynamics normalize over time. Habitual

physical exercise may produce a reduction in resting heart rate, systolic, and diastolic

blood pressure and a decreased submaximal exercise heart rate, minute ventilation, and a

decreased peak exercise diastolic blood pressure (Niset, Hermans, & Depelchin, 1991).

There may also be an increase in peak exercise heart rate, systolic blood pressure, double

product (heart rate multiplied by systolic blood pressure), heart rate range, ventilatory

threshold, and maximal ventilation. Overall, this leads to an improved submaximal

exercise endurance and physical work capacity accompanied by a reduction in exercise

perceived exertion. Other benefits include increased lean body mass, improved

symptoms of fatigue and dyspnea, and a reduction in problems associated with

immunosuppressive therapy (Badenhop, 1995).

There are many factors that are capable of interfering with the ability to exercise

effectively. Personal characteristics such as age and weight of the individual may affect

the ability to perform exercise. The older individual is less likely to engage in activity

than a younger individual. Obesity has numerous health implications associated with it

and thus may interfere with the ability to exercise. Many disease processes that affect

cardiac output, blood flow, and respiration also interfere with exercise performance.

Medications classified as antihypertensives, beta-adrenergic blockers, steroids, and

immunosuppressants produce adverse reactions such as dizziness, fatigue, tremor, muscle

weakness, loss of muscle mass, fluid retention, and bradycardia, all of which can directly

affect the ability to exercise. The ability to participate in physical activity can also be









influenced by psychosocial characteristics such as mood, motivation, social support and

financial situation (Ades & Coello, 2000; Badenhop, 1995; Powers & Howley, 1996).

The transplanted heart has a normal functioning coronary artery system and the

same anatomical structure as the natural heart. However, the transplanted heart is

denervated, and hemodynamic responses are different than the normal innervated heart.

Both afferent fibers (sensory nerves) and efferent fibers of both the sympathetic and

parasympathetic nervous systems are severed. Some of the changes as a result of

denervation include a higher than normal resting heart rate of 90-110 beats per minute,

blunted hemodynamic response to exercise and other stressors, abnormal diastolic

function, orthostatic hypotension, absence of angina, altered response to cardioactive

medications, and lack of response to vagal maneuvers (Cotts & Oren, 1997; Rourke,

Droogan, & Ohler, 1999).

During exercise, cardiac function is altered in the transplanted heart. At the

beginning of exercise, the heart rate response rises slowly and is dependent on the level

of circulating catecholamines in the blood. In addition, blood pressure and cardiac output

response are also delayed. In the first few minutes of exercise, the exercising muscle

provides an increase in stroke volume and is the primary contributor of increasing cardiac

output (Clough, 1990). Peak exercise heart rate is lower and is achieved during the early

recovery phase of exercise instead of during peak exercise intensity. Following exercise,

heart rate elevation is prolonged and slowly returns to pre-exercise levels (Kobashigawa,

1999). Oxygen uptake is decreased during exercise, thus delivering less oxygen to the

exercising muscles. This results in both a lower anaerobic threshold and decreased

exercise tolerance. Peak oxygen uptake is typically 60-70% of predicted values of age-









matched individuals (Dec, 1998). Ventilation is significantly higher but does not increase

delivery of oxygen into the blood.

Exercise Adherence

Although the benefits of exercise has been shown to prevent disease and

contribute to health and well-being, only a small percentage of all individuals engage in

exercise programs with regularity to achieve optimal benefits. Dishman (1988) reported

that 50% of individuals who begin a self-monitored exercise program drop out in the first

six months. Astoundingly, in the United States (US) alone, 40% of adults do not

participate in regular physical activity, while only 15% of adults engage in physical

activity thirty minutes or longer, five days or more a week (Office of Disease Prevention

and Health Promotion, 2001). The remainder of adults exercising are active only

sporadically and it is uncertain as to the achievement of health benefits (Dishman &

Buckworth, 1996). Recent recommendations from the Center for Disease Control and

Prevention (CDC) and the American College of Sports Medicine (ACSM) state that

"every US adult should accumulate 30 minutes or more of moderate intensity physical

activity on most, preferably all days of the week" (Center for Disease Control and

Prevention, 2001).

Encouraging individuals to initiate and adhere to exercise programs has been

noted in the literature to be quite challenging. Engaging in physical activity is a time-

consuming event that takes considerable effort from the individual. It is often negatively

viewed because the consequences associated with it are viewed as negative. The

performance of physical activity is often accompanied by sweating, discomfort,

exhaustion, and the experience of delayed onset muscle soreness. Also, it may be several









weeks or months before the exercising individual is able to perceive any noticeable

changes. Older individuals with chronic diseases may view physical activity as negative

because they may believe that it may do more harm than it would benefit them (Chao,

Foy, & Farmer, 2000).

Adherence to exercise, whether in a structured program or outside of a formal

program, has been linked to many variables, both physiological and nonphysiological.

The variables have been categorized as situational or environmental, physical,

psychological, health-related, behavioral or social, and previous exercise-related habits

(Gale, Eckhoff, Mogel, & Rodnick, 1984; Sullivan, 2001). The variables categorized as

situational that have been previously studied include convenience, time, climate, group

size, money, and facilities, among others. Some physical factors are age, gender, body

weight, heart rate, systolic blood pressure, maximal oxygen consumption (VO2 max) and

injuries. Psychological variables are described as self-motivation, attitude, personality

and beliefs. Other health-related variables include smoking, co-morbidities or disease,

and exercise training among others. Variables categorized as social are social support

and reinforcement.

Identification of specific variables related to an individual's exercise adherence

plays a vital role in maximizing the beneficial effects associated with physical activity.

This enables practitioners to develop strategies to effectively individualize exercise

treatment and protocols. Individualizing exercise prescription and implementing planned

interventions through the use of education and behavior modification can increase

maintenance of physical activity approximately 50% to 60% (Dishman, 1991). It is

essential for the heart transplant recipient to acquire and maintain regular exercise









patterns because of the daily and lifelong requirements of immunosuppressive medical

therapy, the increased risk for the development of osteoporosis, hypertension, and graft

atherosclerosis, and the pre-operative effects of deconditioning. In this population, it is,

therefore, of greater importance to identify factors that interfere with the ability to adhere

to exercise so that the clinical benefits of exercise are obtained. However, predictors of

exercise adherence after heart transplantation have not been previously identified in the

research literature. It is therefore the goal of this research to address this gap in the

knowledge base for heart transplant recipients.

Problem Statement

It is well known that exercise produces many positive physiological and

nonphysiological effects. In order to perform exercise effectively, there are many factors

that must be considered. Some of these factors are an efficient cardiovascular and

respiratory system to pump oxygenated blood to the exercising muscles, adequate diet to

supply needed nutrients to the body, and positive attitude, motivation and support system.

In heart transplantation surgery, the technique employed to anastomose the donor heart to

the native vessels can affect atrial function, thus affecting cardiac performance. In

addition, it is known that there are numerous characteristics and factors that may interfere

with the ability to effectively adhere to exercise. Some of these factors have been

previously identified. The ability to adhere to exercise after heart transplantation may be

problematic due to a preexisting debilitating condition and multiple risk factors

associated with triple drug immunosuppressive therapy post transplantation.

The mainstay of clinical research in heart transplantation has focused closely on

assessing the individual and the response to exercise in terms of cardiopulmonary









outcomes. Although very important, determining the response of the newly implanted

heart to the stress of exercise has given rise to more precise exercise prescriptions for this

population. Specific to the heart transplant recipient, what has not been precisely

identified in the research literature are those factors that predict an individual's adherence

to exercise after heart transplantation so that he/she may benefit from the positive

outcomes of exercise. The problem statement for this study was the following: What

factors are predictive of adherence to exercise after heart transplantation?

Statement of the Purpose

The major purpose of this research was to identify the pre-operative factors,

physical factors, psychological factors, situational factors, disease-related factors and

social influences that are predictive of adherence to exercise after heart transplantation.

A secondary purpose was to identify the combination of pre-operative, physical,

psychological, situational, disease-related factors and social influences that best predict

adherence to exercise after heart transplantation.

Research Questions

The research questions for this study were as follows:

1. What are the pre-operative factors that are predictive of adherence to
exercise after heart transplantation?

2. What are the physical factors that are predictive of adherence to exercise
after heart transplantation?

3. What are the psychological factors that are predictive of adherence to
exercise after heart transplantation?

4. What are the situational factors that are predictive of adherence to exercise
after heart transplantation?

5. What are the disease-related factors that are predictive of adherence to
exercise after heart transplantation?










6. Is social influence predictive of adherence to exercise after heart
transplantation?

7. What combination of pre-operative, physical, psychological, situational,
disease-related factors and social influences best predict adherence to
exercise after heart transplantation?

Significance of the Study

The ability to identify factors that are predictive of exercise adherence after heart

transplantation may lead to interventions that improve exercise ability by identifying

those factors that can then be changed and/or modified. Increasing the capability to

adhere to exercise will increase the chance of experiencing the positive benefits

associated with regular exercise.

It is well documented that regular physical activity lowers the prevalence of

cardiovascular risk factors. Some of the risk factor modifications that occur are

prevention of the development of hypertension by lowering blood pressure and

decreasing left ventricular hypertrophy, improved glucose metabolism in diabetes by

increased sensitivity to insulin, decreased production of glucose by the liver and

increased number of muscle cells utilizing more glucose than adipose cells. It is

estimated that over 50 million Americans try to lose weight each year. Regular exercise

contributes to weight loss by reducing body fat and improving body composition.

Physical activity can significantly decrease total cholesterol, low-density lipoprotein

(LDL) cholesterol, and increase high-density lipoprotein (HDL) cholesterol, thus

reducing cardiovascular risk.

For the heart transplant recipient, regular exercise training has a beneficial effect.

In the heart, there is a significant peak heart rate increase and heart rate responsiveness









seen during the performance of exercise. Another major positive effect of regular

exercise is strengthening of skeletal muscles, thus combating the problems associated

with immunosuppressive therapy such as muscular atrophy and osteoporosis.

Research investigating the quality of life of heart transplant recipients has shown

tremendous improvements in both subjective and objective indicators (Lough, Lindsey,

Shinn, & Stotts, 1985). Subjects experienced positive changes in health status, physical

endurance, sense of achievement, and future outlook. Regular exercise also produces

positive psychological benefits such as improved mood, self-concept and overall well-

being. Stress reduction can also be achieved through regular physical exercise and may

decrease depression and anxiety.

Nursing

Nurse clinicians are in a vital position to promote health and positive health

behaviors. Nursing interventions to promote physical activity can be instituted at any

level and at any location where nurses interact with clients. Knowledge of factors that

predict exercise adherence for the heart transplant recipient allows nurses to assist in

improving the health of these patients by positively impacting a lifestyle change through

education and assistance with an exercise program. Promoting a healthy lifestyle can

also be provided through education on prevention and risk factor modification in an effort

to decrease mortality from coronary heart disease. Assisting the heart transplant recipient

in health promotion activities such as physical activity is one of the leading health

indicators of Healthy People 2010 (Office of Disease Prevention and Health Promotion,

2001).









Health Care and Society

In the United States, there will be approximately 70 million individuals 65 years

and older by the year 2030. Those 85 years and older will represent the fastest growing

portion of the population. With the advancing age of the population, it is imperative to

intervene and decrease the problems that are associated with the aging process, most

notably, cardiovascular disease. With the advancement in technology for heart

transplantation, that is, improved surgical techniques, methods of detecting rejection and

preservation of the heart, and superior immunosuppressive drugs, there may possibly be

an increase in the number of older individuals that become heart transplant candidates.

Thus, the ability to identify factors that are predictive of exercise adherence after heart

transplantation is crucial. The ability to perform exercise is an effective intervention to

reduce and/or prevent functional declines that are associated with the aging process.

Exercise can prevent the loss of muscle mass associated with aging, improve postural

stability, increase flexibility and range of motion and improve bone health, thus reducing

the development of osteoporosis and the risk of falling and related injuries.

Improved adherence to exercise may also reduce the risk of other diseases such as

colon cancer. Risk reduction and promotion of a healthy lifestyle may decrease the need

to seek additional medical therapy or surgical intervention. As a result, the number of

hospital admissions may be reduced.

Summary

This chapter introduced the topic of heart transplantation with emphasis on the

stages of heart transplantation, exercise in heart transplantation patients, and exercise

adherence. A statement of the problem was discussed followed by the statement of the






15

purpose of this research study. Seven research questions were identified. The

significance of the study with reference to nursing, health care, and society was also

addressed. The theoretical framework and a review of the literature are discussed in

Chapter 2.














CHAPTER 2
REVIEW OF LITERATURE

This chapter presents and discusses the theoretical framework for this study. A

review of the pertinent literature related to the major study variables is also presented.

Theoretical Framework

The theory of planned behavior served as the framework for this study. The

theory of planned behavior (Ajzen, 1991) is a modification of the theory of reasoned

action (Ajzen, 1980). A primary goal of this theory is to be able to understand and

predict social behaviors and their outcomes. It was developed based on the limitations

that were discovered in the original model in that there are behaviors over which people

do not have complete volitional control. Behaviors, as explained by Ajzen, are located at

some point along a continuum that extends from total control to complete lack of control.

Those behaviors under total control are said to exist when there are no constraints to

adopting a new behavior. On the other hand, a complete lack of control is present if

adoption of the behavior requires opportunities, skills or resources that are currently

lacking. Most behaviors performed by an individual depend to some degree on

nonmotivational factors such as the availability of opportunities and extraneous resources

such as time, money, skills, and the cooperation of others. The most important

determinant of one's behavior according to this theory (Figure 2-1) is the individual's

intention to perform a behavior. It is assumed that behavioral intentions take into account

the motivational factors that influence a given behavior. This gives insight into how









much effort individuals put into performing a behavior. Generally speaking, the stronger

the intention to elicit a behavior, the higher the likelihood of the performance taking

place.



Behavioral Attitude Toward
Beliefs The Behavior



Normative Subjective Intention Behavior
Beliefs Norm



Control Perceived
Beliefs Behavioral
Control

Figure 2-1. Theory of Planned Behavior (Ajzen, 1991).


The main determinants of intention in the theory of planned behavior are a

combination of three conceptually independent components. The first component is the

attitude toward the behavior. This is the degree to which an individual has a favorable or

unfavorable evaluation of the behavior. Subjective norm is the second predictor and it

reflects the perceived social pressure or influence to perform or not to perform the

behavior. The third component of intention is perceived behavioral control. This can

directly influence behavior in situations where the behavior is not under total volitional

control of the person. Perceived behavioral control refers to the perceived ease or

difficulty of adopting the behavior. It involves internal factors such as past experience,

ability and skill, in addition to anticipated obstacles or external factors such as social

support, time and money. The more favorable the attitude toward the behavior and the









subjective norm, and the greater the perceived behavioral control, the stronger the

individual's intention will be to perform the behavior. Attitude, subjective norm, and

perceived behavioral control will vary in importance across behaviors and situations in

the prediction of behavioral intention.

It is the intent of the theory of planned behavior to explain human behavior and

not just predict it. The theory also involves antecedents to attitudes, subjective norms, and

perceived behavioral control. These antecedents are a structure of beliefs that lead to

attitudes, subjective norm and perceived behavioral control that determine one's actions

and intentions. In basic terms, the theory suggests that behavior deals with salient

information, or beliefs that are relevant to the behavior. Attitudes toward a behavior are

influenced by behavioral beliefs, beliefs that underlie subjective norms are normative

beliefs and control beliefs provide the basis for perceived behavioral control.

Behavioral Beliefs

Attitudes are usually sensibly developed from the beliefs one holds regarding the

object of the attitude. Mainly beliefs are formed about an object by linking it with other

attributes such as in association with other objects, characteristics, or events. Regarding

the determinant attitude toward the behavior, each associated belief links the behavior to

a particular outcome, or to an attribute in which there is some cost incurred when

performing the behavior. Because the attributes that are to be linked with the behavior

already have a positive or negative value associated with them, the individual

involuntarily acquires an attitude toward the behavior. Individuals have a tendency to

favor those behaviors believed to have desirable consequences and for those behaviors









that have undesirable consequences, there is the tendency to form unfavorable attitudes

toward the behavior.

Normative Beliefs

Normative beliefs relate to the likelihood that important others such as a person's

spouse, close friend or a group approve or disapprove of performing a certain behavior.

The strength of the normative belief is determined by individuals or groups and by the

individual's motivation to comply with the expectations of these significant others.

Control Beliefs

Control beliefs are concerned with the presence or absence of opportunities and

resources available for performing the behavior. There are many factors involved in

forming control beliefs. They may be based on an individual's past experience of the

behavior, influenced by second-hand information regarding the behavior, from the

experiences of friends or acquaintances, or by those things that increase or reduce one's

perception of the difficulty of performing the behavior. The fewer the obstacles

anticipated and the more opportunities and resources believed to be possessed by the

individual, the greater their perceived control should be over the behavior.

The purpose of this research study was to identify factors that are predictive of

adherence to exercise after heart transplantation. The performance of exercise was the

main behavior or outcome variable according to the Theory of Planned of Behavior

(Figure 2-2). To determine the individual's intention to exercise, the attitude toward the

behavior was measured by asking the question, "What are the psychological factors that

are predictive of adherence to exercise after heart transplantation?" To determine the

behavioral beliefs associated with this component, the factors that were measured were












FACTORS Attitude Toward The Behavior:
WAttitudhat are the psychological factors
that are predictive of adherence to
Motivation exercise after heart transplantation?


FACTORS
Perceived Social Subjective Norm:
influence Is social influence predictive of Intention Exercise
adherence to exercise after heart
transplantation?


FACTORS

Pre-Operative: Perceived Behavioral Control:
#Days on Waiting List What are the pre-operative,
Functional Status physical, situational, and
NYHA Classification disease-related factors that are
predictive of adherence to
Physical: exercise after heart

Weght transplantation?
Ejection Fraction
Comorbidities
Resting HR/BP

Situational:
Support System
Financial Concerns
Convenience
Climate

Disease-Related:
# Rejection Episodes
# Days Since Rejection
Length of
Hospitalization
Symptoms



Figure 2-2. Predictors of Adherence to Exercise After Heart Transplantation:
Theoretical Framework.



attitude and motivation. The subjective norm component was addressed by asking the


question, "Is social influences predictive of adherence to exercise after heart


transplantation?" Measuring the factor, perceived social influence identified the

normative beliefs of this component. The perceived behavioral control component was

measured by asking the question, "What are the pre-operative, physical, situational, and


disease-related factors that are predictive of adherence to exercise after heart









transplantation?" To measure the control beliefs of this component, the following factors

were measured: pre-operative factors include number of days on the heart transplant

waiting list, functional status six months preceding surgery, and NYHA classification;

physical factors are age, weight, ejection fraction, comorbidities, resting heart rate and

resting blood pressure; situation factors are support system, financial concerns,

convenience, and climate; and disease-related factors are number of rejection episodes

since surgery, number of days since last rejection, number of days of hospitalization after

surgery, and symptoms.

Review of Literature

This literature review includes a discussion of the study variables according to the

theoretical framework, the Theory of Planned Behavior. The first component of this

theory, attitude toward the behavior, addresses the two variables attitude and motivation.

The variable perceived social influence is discussed and represents the second

component, subjective norm. The third theoretical component, perceived behavioral

control, includes the study variables waiting list, NYHA classification, functional status,

symptoms, age, weight, ejection fraction, comorbidities, resting heart rate and blood

pressure, support system, financial concerns, convenience and climate, length of

hospitalization, and rejection factors.

Attitude Toward the Behavior

Attitude toward the behavior includes the psychological factors that are predictive

of adherence to exercise after heart transplantation. The two major factors studied are

attitude and motivation.









Attitude

In general, a positive attitude usually results in a positive outcome. Attitudes

shape the behavior of the individual especially in the performance of exercise. Shephard

(1985) reviewed different factors that shaped the exercise behavior of subjects. In

general, he reports that those who are physically active and take part in regular exercise

have more positive attitudes.

Dishman (1994) reviewed exercise patterns in relation to age. Although he

reports that few differences exist between younger and older subjects, those over 65 years

of age have a positive attitude toward exercising, yet, they perceive to have little control

over being active. In addition, older adults who are sedentary do not have any intention

of beginning an exercise program.

King, Blair, Bild, Dishman, Dubbert, Marcus, Oldridge, Paffenbarger, Powell and

Yeager (1992) reviewed the literature regarding determinants of physical activity and

reported that the belief that exercise is of little value was related to early drop-out of

exercise programs and exercising less frequently than those with opposite viewpoints and

attitudes. Additionally, individuals who perceived themselves as being in poor health

were reported to participate less in structured exercise programs.

A study to investigate the relationship between factors and compliance in an

exercise program among 639 male subjects was conducted by Andrew, Oldridge, Parker,

Cunningham, Rechnitzer, Jones, Buck, Kavanagh, Shephard, Sutton, and McDonald

(1981). A 60-item questionnaire was developed by the investigators and was self-

administered by the subjects. To measure the attitude of the individual, subjects

responded to questions regarding the perceived value and belief in the benefits of









exercise. As expected, those subjects that dropped out early from the exercise program

did not have a strong belief in the value of exercise.

Motivation

Self-motivation is reported consistently in the literature to correlate with

adherence to physical activity. Noted for his pioneering work in motivation and

adherence to therapeutic exercise, Dishman (1981) developed a valid and reliable self-

report measure of self-motivation. This Self-Motivation Inventory has been used in

many population studies and it has been reported that self-motivation positively

correlated with physical activity (King et al., 1992). Dishman, Ickes, and Morgan (1980)

found that motivation was attributed to being the best discriminator between those who

enroll and adhere to an exercise program and those who enroll and drop out.

The Self-Motivation Inventory was completed by a group of healthy subjects

prior to participating in a six-month exercise program (Gale, Eckhoff, Mogel, & Rodnick,

1984). Thirty-three men and 73 women participated. The subjects were grouped

according to exercise adherence patterns after program completion and were categorized

as early drop-outs, nonadherers, or adherers. Men who were categorized as early drop-

outs, i.e., attending less than 10% of exercise sessions, were found to have the lowest

self-motivation scores as compared to women of the same category and those with

superior attendance rates.

Welsh, Labbe, and Delaney (1991) investigated personality variables and the

application of cognitive strategies to adherence to exercise. Twenty-six sedentary women

were assigned to two groups to begin a jogging program. One group was given exercise

instructions and verbal reinforcement during their exercise, the second group received the









same intervention as group one and they were also taught cognitive strategies to use

during their exercise. None of the subjects had attempted a previous running program.

Sixty percent of the subjects were at least 20% over ideal body weight. The Self-

Motivation Inventory was one of the questionnaires administered at the beginning of the

program. During the program, four subjects dropped out from exercising. Six weeks after

the completion of the exercise program, a follow-up was conducted and eight subjects

had quit exercising; however, 64% were still exercising. Six months following

completion of the program, only 17 subjects could be contacted and of those 64% were

still exercising. The researchers found no significant overall correlation between scores

on the Self-Motivation Inventory and exercise compliance. The average score for the

SMI was 132.12 out of a total possible score range of 40 to 200. However, they did find

that when comparing the subjects who exercised for a minimum of three times per week

with a target heart rate with those subjects that did not, the subjects who complied with

exercise had a significantly higher set of scores on the SMI than those subjects who did

not comply.

Self-motivation and mood were evaluated at the beginning of a rowing training

program in 84 college freshman women (Raglin, Morgan, & Luchsinger, 1990). Physical

performance also was initially evaluated with 44 subjects completing a standardized

rowing ergometer task. At the end of the training season, 22 women had adhered to the

training, while 64 dropped out. It was found that scores on the Self-Motivation Inventory

were significantly lower (p<.05) among the drop-outs compared to the adherers. Drop-

outs also took significantly longer to complete the rowing ergometer task compared to

adherers (p<.05). Data analysis also revealed that ergometer time and self-motivation









correlated (-.47, p<.01), indicating that a shorter time to complete or superior

performance on the rowing ergometer task was associated with higher self-motivation.

Subjective Norm

Subjective norm involves the perceived social influence that is predictive of

adherence to exercise after heart transplantation. Social influences are important in

regard to opportunities, behaviors and consequences. One's motivation to exercise may

therefore be formed by those social influences. However, measuring social influences on

exercise behavior has received very little attention in the research literature.

Booth, Owen, Bauman, Clavisi, and Leslie (2000) identified social-cognitive

variables and perceived social and environmental influences on physical activity. Four

hundred 49 Australian adults age 60 or older were randomly selected to complete a

physical activity questionnaire. This questionnaire was submitted along with the

Population Survey Monitor that was distributed by the Australian Bureau of Statistics.

They assessed for social influence by examining the frequency that family and friends

reported that physical activity appeared good for another's appearance, if they got upset

regarding the activity the subject wanted to participate in and if they criticized the subject

about the activity in which they wanted to participate. The social reinforcement variable

appearance ("others say activity is good for appearance") was the only variable that was

significantly related to physical activity (p = .01). In addition, those subjects in the

physically active group received a higher percentage of positive social reinforcement

regarding the appearance variable (43.8%) than those in the inactive group (31.7%).









Perceived Behavioral Control

Perceived behavioral control involves the pre-operative, physical, situational, and

disease-related factors that are predictive of adherence to exercise after heart

transplantation.

Pre-operative Factors

The pre-operative factors studied include number of days on the heart transplant

waiting list, functional status, and NYHA Classification.

Waiting list

During the waiting period for heart transplant surgery, the performance of

exercise is extremely important. Besides gaining the beneficial effects of exercise, it

serves as a diversion from the prolonged undetermined waiting period. Muscle

strengthening and aerobic exercise helps condition muscles in an effort to prevent

deconditioning that can occur after transplantation.

Each year the number of patients on the heart transplant waiting list continues to

increase and the availability of donor hearts decreases. As a result, the waiting time for a

donor heart lengthens. At the end of June 2001, there were 4,231 patients awaiting a

heart transplant. In the previous six months, over 300 patients died while on the waiting

list and over 1,100 received a new heart (UNOS, 2001). The mean waiting time for a

transplant candidate in 1999 was 217 days with an approximate mortality rate of 24%.

Severity of illness is associated with the classification of heart transplant

candidates according to UNOS and impacts waiting time. Those classified as status 1

have a more medically unstable condition and are hospitalized usually in an intensive

care unit. Individuals in this status may often require invasive hemodynamic monitoring,









mechanical ventilation, diagnostic procedures and the use of vasoactive medications

among other interventions. As the waiting period progresses in these individuals, further

decompensation ensues increasing the unlikelihood of receiving a heart transplant. Status

2 candidates often reside in their home awaiting organ donation. Although they continue

to be functional, their tolerance to physical activity is compromised due to the nature of

their disease state. As waiting time for a heart transplant increases, worsening of their

disease with increasing signs and symptoms occurs as time progresses and often they are

changed to status 1 while on the waiting list for organ transplantation (Tahan, 1998).

As the organ waiting period is prolonged, deconditioning secondary to chronic

heart failure becomes more severe (Rader & Vaughen, 1994). Studies have shown that

chronic heart failure is associated with abnormal muscle metabolism and skeletal muscle

atrophy leading to reduced ability and capacity to exercise (Drexler, 1992).

Transplant waiting time was selected as a clinical variable to determine its

predictability of submaximal exercise capacity before hospital discharge and on maximal

exercise capacity at approximately four months post hospital discharge in a study by

Salyer, Jewell, and Quigg (1999). Total transplant mean waiting time was 122 days 140

days (SD). Waiting time among the subjects varied between 3 to 516 days. In this study,

total transplant waiting time did not correlate with predischarge submaximal exercise

capacity (r = .25; p = .24), nor did it correlate with postdischarge exercise capacity. Total

transplant waiting time was not predictive of either outcome variable in the study.

Because waiting time was found not to be predictive of exercise capacity, this variable

needs to be studied further.









Functional status

End-stage heart disease (ESHD) can have profound deconditioning effects on the

body. Also, surgery and prolonged hospitalization can result in severe deconditioning on

the body. As in chronic heart failure, the pathophysiologic and compensatory events that

are associated with the disease often leave the individual bedridden in poor functional

status.

The effects of end-stage heart disease are characterized by forward failure of the

left ventricle producing a diminished cardiac output and backward failure resulting in

pulmonary and hepatic congestion (Futterman, 1988). Signs and symptoms that are

characteristic of ESHD are ventricular dilatation and severely diminished systolic

ejection leading to myocardial failure, decreased cerebral tissue perfusion producing an

alteration in neurological status, and increased respiratory effort. Other signs indicative

of right ventricle failure include peripheral edema, atrial and ventricular gallops,

hepatomegaly, ascites, jugular vein distention, presence of murmurs and alterations in

blood pressure.

Prolonged bedrest and immobility have profound deconditioning effects on the

body that result in functional impairments such as impaired ambulation and activity

intolerance. The deconditioning effects of prolonged immobility affects all body

systems. For example, the cardiovascular responses from prolonged bedrest include

decreased cardiac output that contributes to a decrease in aerobic capacity, postural

hypotension, increased cardiac workload, and venous stasis. The changes that occur in

the musculoskeletal system are muscle atrophy, loss of muscular strength and a decrease

in muscle oxidative capacity that contribute to a decline in aerobic and functional









capacity. Additional musculoskeletal changes that occur are osteoporosis, osteoarthritis,

and contractures. Other changes that occur are sensory deprivation, pressure ulcers,

atelectasis, and hypoxemia (Rader & Vaughen, 1994).

Grady, Jalowiec, and White-Williams (1998) investigated indicators of severity of

illness and quality of life six months after heart transplantation. The two indicators

studied were NYHA classification and UNOS status. Typically, UNOS status I are those

individuals hospitalized in the intensive care unit receiving inotropic support or receiving

either cardiac or pulmonary mechanical support. UNOS status 2 are all other individuals

listed for heart transplantation. In a nonrandom sample of 219 adult subjects, the

researchers found that subjects who were UNOS status 1 or NYHA class IV before

transplantation were less satisfied with existing state of health and physical functioning at

six months posttransplantation. They reported that UNOS status 1 patients experienced

significantly more disability in performing ambulation six months after surgery that those

in UNOS status 2 category.

NYHA classification

The New York Heart Association (NYHA) classification system was developed

as a simple method to measure functional capacity according to the severity of heart

failure. As described elsewhere, patients are classified into one of four functional classes

that depend on the degree of effort that is needed to elicit symptoms. The symptoms of

heart failure worsen when progressing from NYHA class I to class IV due to a decrease

in ejection fraction that occurs over time (Packer & Cohn, 1999). As a result, individuals

often experience symptoms of angina, shortness of breath and fatigue that result in

exercise intolerance.









Riedinger, Dracup and Brecht (2000) performed a secondary analysis on data that

were previously collected in the Studies of Left Ventricular Dysfunction. Their aim was

to identify predictors of quality of life in 691 women with heart failure with physical

functioning as one of the main dimensions in quality of life. NYHA classification was

found to be a strong predictor and the second most predictive factor of global quality of

life, vigor, intermediate activities of daily living and social activity. They found that as

NYHA classification increased there was a decrease in general life satisfaction, vigor,

basic and intermediate activity in daily living scores, social activity, and general health.

Higher NYHA classification was also associated with an increased perception that the

individual's state of health interfered with the performance of normal activities.

Salyer, Jewell, and Quigg (1999) investigated clinical parameters that would

predict submaximal exercise capacity in heart transplant recipients. In their study, they

developed their own severity of heart failure score. Transplant recipients were assigned a

description code at the time of their surgery to denote this score. The description code

was identified as follows: 1 = working or attending school full time, 2 = working or

attending school part time, 3 = homebound or failing to thrive, 4 = hospitalized, 5 =

hospitalized in intensive care, and 6 = on life support. Of the 24 heart transplant

recipients studied, sixteen were hospitalized and eight had been at home awaiting

surgery. The mean pretransplant severity of heart failure score was 3.6 (SD 1.5).

Statistical analysis did not show pretransplant severity of heart failure score to be

predictive of exercise capacity after discharge from the hospital.









Physical Factors

The physical factors studied include age, weight, ejection fraction, comorbidities,

resting heart rate, and resting blood pressure.

Age

Advancing age has been associated with an increasing risk of functional decline

and a decrease in the total amount of time spent participating in physical activity. It has

been found that physical activity decreases with age starting after late adolescence and

the decline in activity continues until after the age of 50 (King, Blair, Bild, Dishman,

Dubbert, Marcus, Oldridge, Paffenbarger, Powell & Yeager, 1992). Dishman (1994)

reports that physical activity may be limited with increasing age due to the deteriorating

health of the individual. Exercise maintenance patterns are described as being poor in all

age groups especially the older individual according to Emery, Hauck, and Blumenthal

(1992). Although almost all the subjects that participated in their study self-reported

continuing in physical activity after one year following exercise training, age was not a

predictor of exercise behavior or overall activity.

In a research study to identify factors that predict exercise adherence in healthy

adults, Gale, Eckhoff, Mogel, and Rodnick (1984) recruited 106 subjects, 33 men and 73

woman to participate in a six-month exercise program. They found that men who were

categorized as early drop outs, i.e., attended less than 10% of all exercise sessions, were

slightly but not significantly younger than those categorized as nonadherers and adherers

combined. However, early drop-out women were found to be significantly younger (27.5

vs. 32.3 years; p< .05).









A study by Ades, Maloney, Savage, and Carhart (1999) was conducted to

measure the effect of a three-month exercise rehabilitation program on physical

functioning. Physical functioning was determined by using the self-administered

Medical Outcomes Short Form Questionnaire. Subject age ranged from 20 to 87 years.

Males represented 74.9% (227) of the study sample and females 25.1% (76). The

average age for males were 60.0 (SD 11.1) and 62.5 (SD 12.0) for females. They

found that patient age was significantly related to physical function scores that were

determined at baseline prior to the exercise program. Older patients who were greater or

equal to 60 years of age in the study had lower baseline physical function (r = -.22;

p<.001).

Salyer, Jewell, and Quigg (1999) investigated exercise capacity after heart

transplantation. The mean recipient age of the subjects was 46.0 10.5 (SD). Age was

not found to be a predictor of predischarge submaximal exercise capacity. However,

when they evaluated postdischarge maximal exercise capacity four months after hospital

discharge, recipient age was inversely correlated with measured peak exercise oxygen

consumption (VO2) (r = -.43; p<.04). This finding was expected because for every

decade after the age of 25, V02 declines approximately 9%. Regression analysis

identified recipient age and two other variables, postoperative length of stay and time

since resolution of rejection, explained 73% of the variance in early posttransplant

estimated peak exercise metabolic equivalents (METs). Age contributed 19.9% to the

explained variance. In regression analysis of peak VO2, only recipient age entered the

model and explained 18.5% of the variance.









Weight

It is estimated that approximately 50 million Americans attempt to lose weight

every year (Mclnnis, 2000). There are many health implications associated with obesity

including hypertension, coronary artery disease, diabetes, hyperlipidemia and many

musculoskeletal conditions. It has been cited that overweight or obese people participate

less frequently in physical activity than normal weight individuals (King, Blair, Bild,

Dishman, Dubbert, Marcus, Oldridge, Paffenbarger, Powell, & Yeager, 1992). In terms

of exercise adherence, Dishman (1981) reported that percent body fat was a significant

discriminator among exercise program participants and length of time of adherence. He

concluded that those individuals who were leaner, lighter and less fit were more apt to

continue in the exercise program for a longer length of time.

Gale, Eckhoff, Mogel, and Rodnick (1984) investigated weight as a factor and its

relationship to exercise adherence among healthy adult subjects. After six months of

group participation in an exercise program, they identified that men and women who

were classified as early drop-outs in their exercise program were less fat than those

nonadhering and adhering men and women. Comparisons were made between adherers

and nonadherers of the exercise program and the results showed that the adhering women

had significantly less weight and percent fat (p<.05). However, no significant differences

of weight or percent fat existed between adhering and nonadhering men.

Studying factors to predict exercise adherence in women, Klonoff, Annechild, and

Landrine (1994) recruited twenty-three subjects to enroll in an aerobics program. The

average weight of the subject at initial assessment was 143.77 pounds. They found a

significant correlation between exercise adherence and weight (r = .52, p<.005). These









results suggested that heavier subjects were more likely to adhere to the exercise schedule

and attend class. Five variables were also reported as being the best subset to predict

adherence to exercise and accounted for 73% of the total variance. Among these five

factors, weight was included and individually contributed 20.7% to the variance.

Ejection fraction

The ejection fraction is a representation of the fraction of diastolic volume that is

ejected from the heart during systole. It is often used as a marker of the state of

contractility of the heart or overall left ventricular performance. Cardiopulmonary fitness

is essential for the performance of physical activity and exercise. A principal factor in

the performance of exercise is the ability of the heart, lungs and circulation to deliver

adequate oxygen to the working muscles. Activity intolerance develops when there is a

lack of supply of energy sources. Disease states such as myocardial infarction and heart

failure can decrease ejection fraction, and cause pain and fatigue, all of which can

influence the balance of energy needed for the performance of activity.

Very little information exists in the research literature utilizing ejection fraction as

a marker to predict exercise tolerance. In fact, Sullivan and Hawthorne (1995) reported

in a published review of heart failure and exercise intolerance that left ventricular

ejection fraction predicts exercise tolerance only to a limited extent.

Clarke, Frasure-Smith, Lesperance, and Bourassa (2000) conducted a secondary

analysis on data from the Studies of Left Ventricular Dysfunction (SOLVD) Prevention

and Treatment trials for the purpose of identifying predictors of functional status in

patients with left ventricular dysfunction. The variables explored were psychological,

social, and physiological. Two thousand nine hundred ninety-three subjects selected for









this study had documented left ventricular ejection fraction of less than or equal to 35%.

Mean ejection fraction of the sample was 26.7% (SD +6.4). A global conclusion was

made concerning several variables and it was stated that individuals with low left

ventricular ejection fraction, who had highly anxious or depressed moods or low vigor

levels, lower socioeconomic status and were non-White had an increased probability of

having serious limitations associated with ADL functions.

Comorbidities

Physical activity plays a primary and secondary prevention role in cardiovascular

disease, reduces the risk of cancer, improves muscle and joint function and builds healthy

bones in those with bone or joint problems, and has psychological benefits (American

Heart Association, 2001). However, the presence of diseases or conditions, whether

primary or secondary to treatment or medications, can hinder and impair the ability of the

individual to perform exercise. Some prevalent cardiovascular comorbidities include

angina, myocardial infarction, heart failure, cerebrovascular disease and peripheral

vascular disease. Arthritic or spine-related comorbidities include knee or hip arthritis,

osteoporosis, disc disease or spinal stenosis. Other comorbidities that are prevalent are

diabetes mellitus, chronic obstructive pulmonary disease, Parkinson's disease, and cancer

(American Association of Cardiovascular & Pulmonary Rehabilitation, 1999;

McDermott, Liu, O'Brien, Guralnik, Criqui, Martin, & Greenland, 2000).

In myocardial infarction, the cardiopulmonary and hemodynamic response to

submaximal and maximal exercise is often altered and results in a subnormal aerobic

capacity (Franklin, 1997). This response is due to a decrease in cardiac output. Scarring

of the left ventricle can further cause a progressive decline in ejection fraction and stroke









volume. A common cardiac symptom during exercise is angina and it is often a

diagnostic indicator of coronary artery disease. Although angina is predictable during

exercise in those diagnosed with stable angina, it can become unstable and progress to an

acute myocardial infarction (Friedman, 1997). Heart failure has a number of

abnormalities that affect the acute response to exercise and involve central, peripheral

and ventilatory factors. A reduced cardiac output is the central feature that leads to a

poor exercise response. Other features include poor lung ventilation and perfusion

leading to shortness of breath, leg fatigue due to blood flow abnormalities and changes in

skeletal muscle metabolism that leads to changes in muscle fiber types among others.

Cerebrovascular disease such as stroke or head injury may interfere with the ability to

exercise and is dependent upon the extent of the injury. Injury involvement may be

demonstrated as spasticity or weakness of the extremities, balance impairment, aphasia

and mental confusion (Palmer-McLean & Wilberger, 1997). The main effect of

peripheral vascular disease is claudication due to inadequate blood flow to the legs.

Arthritic conditions have both articular and systemic involvement and can affect

pulmonary and cardiac function in addition to causing vasculitis. Acute inflammation of

the joints can cause pain, swelling and stiffness leading to restricted range of motion and

deconditioning of the muscles (Minor & Kay, 1997). Osteoporosis frequently leads to

bony fractures that can hinder the performance of exercise. Vertebral fractures are often

common and can lead to kyphosis and result in frequent falls (Bloomfield, 1997).

Diabetes mellitus predisposes the individual for developing microvascular

complications that include peripheral neuropathy, retinopathy, nephropathy and others.

Also, endogenous insulin concentrations do not respond normally during exercise. This









results in an imbalance between peripheral glucose utilization and glucose production by

the liver (Albright, 1997).

The effect of chronic pulmonary diseases on the exercise response is varied

depending on the primary impairment involved with the disease. Many individuals may

experience impaired expiration with obstructive disease and decreased inspiratory

capacity with restrictive diseases. These result in increased respiratory rates,

hyperinflation, diminished tidal volumes and worsening respiratory efficiency (Cooper,

1997).

In Parkinson's disease, there is dysfunction of the autonomic nervous system that

interferes with thermal regulation, heart rate, blood pressure and position changes during

exercise. Also, exercise efficiency is decreased due to muscle rigidity, loss of upright

posture and movement disorders that are often seen in Parkinson's. As a result, heart rate

and oxygen consumption may be higher during submaximal exercise (Protas, Stanley, &

Jankovic, 1997).

Cancer and its effect on exercise is dependent on the manifestation of symptoms

and the prescribed treatment to eradicate the cancer cells. Overall, individuals

undergoing cancer therapy are easily fatigued. Surgical procedures can cause pain, loss

of movement and flexibility and sensory and nerve damage. Many chemotherapeutic

agents can cause cardiomyopathy, anemia and pulmonary fibrosis all affecting the ability

to exercise (Selby, 1997).

A study to examine the effects of physical functioning and cardiac rehabilitation

was conducted by Ades, Maloney, Savage, and Carhart (1999). Three hundred three

subjects with known coronary heart disease were selected to participate in three months









of exercise training as part of a rehabilitation program. The ages ranged from 20 to 87

years and 74.9% of the subjects were male. Baseline data collection consisted of the

Medical Outcomes Short-Form Questionnaire, Geriatric Depression Questionnaire,

symptom-limited exercise treadmill test, strength measures, and assessment of the

presence ofcomorbid conditions. Comorbid conditions, if present, were quantified by

their severity. The comorbid score was identified as follows: 1 = comorbid condition

present by not exercise limiting, 2 = present and resulted in an impact on the exercise

response, and 3 = exercise limiting. The comorbid conditions assessed for were diabetes,

cerebrovascular disease, peripheral vascular disease, chronic obstructive pulmonary

disease and arthritis. Comorbidity was found to be a significant predictor of the subject's

baseline physical function score (r = -.23, p = .001) along with maximal exercise

capacity, peak aerobic capacity, leg and upper body strength, depression score and age.

The presence of comorbidities predicted poor physical function in this group of subjects.

Caruso, Silliman, Demissie, Greenfield, and Wagner (2000) used a cross-sectional

study design to study factors predictive of impaired physical function specifically in

individuals with Type 2 Diabetes. One thousand two hundred thirty-eight individuals

who were 55 years or older completed a mailed questionnaire that included the Short-

Form 36, health behaviors, demographic and diabetic information, comorbidity questions,

and assessment of depression. They found eight independent variables that predicted

impaired physical function (R2 = .40, p< .05). Of these eight variables, comorbidity as

measured by the Total Illness Burden Index, had the strongest association with impaired

physical function.









Resting heart rate and blood pressure

The physiologic variables, resting heart rate and resting blood pressure and their

association with exercise program participation and adherence has received very little

consideration in the research literature. A retrospective study by Dishman (1981)

investigated biological variables and their association with exercise adherence and

coronary heart disease. Profiles for male subjects were retrieved from an exercise

program that was conducted over a five-year period. The parameters assessed that are

pertinent to this study were resting heart rate, resting systolic and diastolic blood

pressure, maximum exercise heart rate, and maximum exercise systolic and diastolic

blood pressure. The results of the study did not show these variables to discriminate

between the exercise program participants and exercise adherence (p >.44 to .90).

Resting heart rate and resting systolic blood pressure were two variables included

in the investigation of exercise adherence for healthy adults as described earlier (Gale,

Eckhoff, Mogel, & Rodnick, 1984). Of the 33 men and 73 women participating in the

study, no correlation was found between these variables and adherence rates to an

exercise program (r = .203, r = .028).

Situational Factors

The situational factors studied include support system, financial concerns,

convenience, and climate.

Support system

The degree of social support provided to an individual impacts adherence to the

performance of exercise. Positive reinforcement or social support has been cited

consistently in the research literature to be related to an increase in adherence to exercise.









Andrew, Oldridge, Parker, and colleagues (1981) investigated personal,

psychosocial, and program-related factors and their relationship to exercise compliance in

post-coronary patients. Seven hundred twenty-eight subjects were randomly assigned to

either a high intensity exercise program or low intensity program based on the risk factors

of occupation, personality, hypertension, and angina. A 60-item self-administered

questionnaire was distributed to the subjects and they received an 87.8% response rate.

Of the total respondents, there were 266 drop-outs and 373 compliers to the exercise

program. It was found that the drop-out rate of those subjects without spousal support

(i.e., spouses were indifferent or negative toward the exercise program) was three times

higher than of those subjects who had spousal support.

Gale, Eckhoff, Mogel, and Rodnick (1984) investigated factors relating to

exercise adherence among healthy adults. Thirty-three healthy men and 73 women

participated in a group exercise program for six months, three times per week. Batteries

of tests were conducted prior to the initiation of the exercise program and attendance was

recorded daily. Analyzing the results, they found that being single was more prevalent in

those subjects classified as early drop-outs (p< .05).

Rogers (1987) studied spousal behaviors that influence the compliance of heart

transplant patients. This descriptive study consisted of six postoperative heart transplant

recipients, four men and two women. Subjects were interviewed by the investigator

using an open-ended, semistructured questionnaire guide in order to elicit responses

regarding their perceptions of their spousal support. This study did not measure spousal

support or compliance. The information obtained from the study suggested that the

supportive behaviors from spouses are primarily informational in nature. Concerning









exercise, spouses suggested taking walks with the patient, suggested alternate ways of

exercising indoors, and provided daily rest periods. To help the subjects maintain their

routine exercise program, all spouses were reported to have participated with the subjects

in their daily walking or bicycling.

In a literature review by King, Blair, Bild, Dishman, Dubbert, Marcus, Oldridge,

Paffenbarger, Powell, and Yeager (1992) they reported that investigators Dubbert,

Stetson, and Corrigan (1991) studied predictors of exercise maintenance in women and

found that family participation and family support strongly predicted exercise

maintenance among women; however, it was not found to be supportive in men. Other

researchers have also reported spousal support and attitude as being a highly important

and consistent influence on adherence to participation in exercise programs (Dishman,

1982; Heinzelmann & Bagley, 1970).

Financial concerns

Participation in structured exercise programs at local gyms or health clubs can be

quite expensive and become a barrier to performing exercise. Inadequate or unavailable

financial resources are a common reason for the lack of participation in exercise

programs where fees are required. Costs involved in purchasing gear and equipment can

also add to the expense. Available research on program factors, i.e., costs, and their

relationship to exercise adherence are limited (King, Blair, Bild, Dishman, Dubbert,

Marcus, Oldridge, Paffenbarger, Powell, & Yeager, 1992).

Heart transplant recipients have already endured a tremendous medical cost

beginning in the pretransplant stage. Frequent hospitalizations, the need for inotropic and

mechanical support, pretransplant evaluation workup, the waiting time, the surgical









procedure, medications, and frequent posttransplant diagnostic evaluations all contribute

to financial strain for the individual and their family (Muirhead, 1989). In addition, the

added burden of loss of employment due to the many hospitalizations further increases

financial strain.

Campbell and Etringer (1999) surveyed 300 heart transplant recipients who were

6 months to 12 years posttransplantation for the purpose of identifying quality of life

indicators, presence of depression, and compliance related behavior. Of the 185 heart

transplant recipients that responded, 27.8% reported that finances were a problem after

transplantation. Finances were among the five most significant problems identified.

Convenience and climate

The physical environment can either help or hinder the performance of physical

activity and its adherence. In a review of the application and promotion of exercise by

Martin and Dubbert (1982), it was stated that investigational studies have found that the

location of the exercise program was inconvenient and detracted significantly from

adhering to participation. A review by Dishman (1994) regarding motivation and

exercise among older adults states that older adults living at home are more likely to

engage in exercise in the atmosphere of their own home than in a structured and

supervised environment. However, Shephard (1985) comments that the convenience of

exercising in a group results in an increase in exercise adherence rates because it provides

an opportunity for socializing and it is preferred for the extroverted individual.

A review on "Physical activity, nutrition, and chronic disease" was published by

Blair, Horton, Leon, Lee, Drinkwater, Dishman, Mackey, and Kienholz (1996).

Reviewing those barriers that prevent the adoption of a healthy lifestyle, it was reported









that inaccessibility to exercise facilities is one of two main reasons for not initiating or

continuing with an exercise program, the other reason is lack of time. It was important to

note that the perception of barriers differed among populations, age groups, and

exercisers and nonexercisers.

In other literature reviews, lack of time is consistently reported to be a significant

barrier and reason for dropping out of exercise programs (Dishman, Sallis, & Orenstein,

1985; King, Blair, Bild, Dishman, Dubbert, Marcus, Oldridge, Paffenbarger, Powell, &

Yeager, 1992; Martin & Dubbert, 1982).

Personal, psychological, and program-related variables and their relationship to

exercise compliance in post-coronary patients were studied by Andrew, Oldridge, Parker

et al. (1981). Seven hundred twenty-eight subjects were randomly assigned to either a

high intensity exercise group or a low intensity exercise group based on four prognostic

risk factors as previously discussed. Completion of a 60-item questionnaire by the

subjects resulted in 266 drop-outs and 373 compliers to the exercise program. The

category of center inconvenience was reported to be significantly related with the high

drop-out rate of subjects. The three questions that were perceived as significant were as

follows: difficult to attend on time, inconveniently located, and difficulty with parking at

the facility.

Disease-related Factors

The disease-related factors studied include rejection factors, length of

hospitalization, and symptoms.









Rejection factors

Allograft rejection after heart transplantation is a major complication and

common cause of mortality despite improvements in immunosuppression. The highest

incidence of acute rejection occurs within the first month after transplantation. It is

attributed to a reaction of the immune system of the recipient to the human leukocyte

antigens of the donor heart (Rourke, Droogan, & Ohler, 1999). Histologically, acute

rejection is characterized by diffuse inflammatory infiltration of mononuclear cells,

myoctye necrosis and hemorrhage and myocardial edema (Niset, Hermans, & Depelchin,

1991). Hemodynamic instability due to left ventricular diastolic dysfunction results with

an accompanying loss of the Frank-Starling mechanism. Reduced cardiac compliance is

responsible for the reduction in stroke volume and cardiac output that is evident during

exercise. Rejection also results in a dramatic reduction in vasodilatation capacity of the

coronary vessels, thereby exposing the myocardium to an increase in oxygen demand.

For these reasons, heart transplant recipients often stop all physical activity during

rejection periods.

Cupples (1997) provided a comprehensive review of heart transplantation and

women. She reported that investigational studies have found, that among female

recipients of heart transplantation, there was an increased occurrence of rejection. An

increase in rejection episodes was more significant within the first 30 days, at 4 months,

and at 12 months after transplantation. Forty-seven percent more females had

experienced rejection than males. It was also noted that women had required more

immunosuppression therapy and significantly higher doses of prednisone.









Again, Salyer, Jewell, and Quigg (1999) investigated time (days) since resolution

of rejection as a clinical variable to determine its effect on exercise capacity in heart

transplant recipients. The number of days since the resolution of the last rejection episode

in the subjects was approximately 18. Most subjects experienced only one rejection

episode within the first four months after transplantation. The number of days to resolve

the rejection episode varied between one and 65 days among the subjects. The results

showed that time since resolution of rejection was positively correlated with estimated

METs at peak exercise at four months after hospital discharge (r = .55, p = .006). Time

since resolution of rejection also was one of three clinical variables that explained 73% of

the variance in predicting early peak exercise METs in the posttransplant period.

Individually, it contributed 29.6% of the explained variance. This study found that the

longer since the last rejection episode, the better their exercise capacity.

Length of hospitalization

Uneventful planned surgical procedures usually have a predetermined number of

hospital days that an individual will spend recuperating prior to his/her discharge home.

It is logical to predict that any occurrences that involve postoperative complications,

noncompliance, pre-operative medical condition of the patient, history of addictions, or

any functional disability would prolong the hospital length of stay in the postoperative

period. Likewise, in the heart transplant recipient, an episode of allograft rejection may

also prolong hospitalization. As the number of days of hospitalization increases, the

patient is delayed from returning to self-care and full activities of daily living. Thus,

recommendations to participate in a rehabilitation program are postponed.









Grady, Haller, Grusk, and Corliss (1990) analyzed the medical records of 65 heart

transplant recipients (12% female, 82% male) in a retrospective study to determine

factors that predict hospital length of stay. The range of hospital length of stay was 15 to

45 days with an average of 24.4 days reported. Three models were generated to predict

length of stay from the data analysis. The factors that represented the pre-operative

model that were significantly related to length of stay were diagnosis, severity of heart

failure, duration of heart disease symptoms and pulmonary vascular resistance. As a

group, these factors accounted for 36% of the variance in length of stay. The second

model included the addition of donor information such as ischemic time, donor sex and

age and size. This model did not account for an appreciable increase in the variance. In

the third model, postoperative factors were added and accounted for 71% of the variance

in hospital length of stay. The significant variables in the final model were duration of

pretransplant cardiac symptoms, pulmonary vascular resistance, pre-operative severity of

heart failure, incidence of postoperative rejection, and transplant program experience.

Psychosocial and medical predictors of hospital length of stay after heart

transplant surgery have been studied. Grady, Jalowiec and White-Williams (1999)

studied pre-operative psychosocial variables and their relationship with hospital length of

stay after heart transplantation in 307 subjects. The sample of subjects consisted of 79%

males and 21% females. The mean length of stay for their subjects was 19.1 days (SD

13.1). Five variables had significant differences on length of stay. Those subjects with

a history of smoking, no history of drug abuse, no financial problems, an adequate

understanding of heart failure and treatment, and complied with pretransplant medical

regime had a longer length of stay. Other pre-operative variables that correlated with









longer length of stay included greater emotional disability and less satisfaction with

significant others and with psychological areas of life. Symptoms related to

dermatological or soft tissue, self-care and ambulation functional disability and a

decrease in satisfaction related to health, and stress related to work, school or finances

showed a significant relationship with longer hospitalization.

Studying predictors of exercise capacity after heart transplantation, Salyer and

coworkers (1999) found that their subjects had a posttransplant hospital length of stay of

14 to 44 days. Although postoperative length of stay did not correlate with either

predischarge submaximal or postdischarge maximal exercise capacity, it did significantly

explain 73% of the variance, along with two other clinical variables, regarding estimated

peak exercise METs in the early posttransplant period. By itself, posttransplant length of

stay contributed 23.6% to the explained variance of postdischarge estimated peak

exercise METs. They concluded that a longer length of hospitalization can result from

complications occurring in the postoperative period. This can add to the deconditioning

effects already seen in the pre-operative phase and may then have an unfavorable effect

on peak exercise METs in early postdischarge.

Symptoms

The presence of physical symptoms has been associated with exercise adherence.

A negative relationship has been reported to occur between the number of symptoms and

exercise adherence; in other words, there is a tendency of individuals who experience

many symptoms to exercise less. On the other hand, individuals who have many

symptoms and are aware of the beneficial effects of exercise and the potential to alleviate

symptoms may actually adhere to a greater extent to an exercise program.









As a result of the nature of the disabling disease or condition or due to the heart

transplant surgery itself, afflicted individuals commonly experience a variety of physical

symptoms. End-stage heart disease patients awaiting a heart transplant reported the

following symptoms occurred often: fatigue, shortness of breath and problems with

physical strength and stamina. Other symptoms that occurred with moderate frequency

included fluid retention, pain, lack of sleep, poor concentration and sexual dysfunction

(Muirhead, Meyerowitz, Leedham, Eastburn, Merrill, & Frist, 1992).

After heart transplant surgery, the individual often experiences a new host of

physical symptoms due to the surgery itself, its potential complications or the effect of

immunosuppression therapy. Lough, Lindsey, Shinn, and Stotts (1985) studied life

satisfaction after heart transplantation and found that all 75 subjects experienced side-

effects due to immunosuppression. Those symptoms that occurred often or always were

bruises, fragile skin, changes in body and facial appearance, poor vision, lack of sleep,

sexual dysfunction, poor concentration, depression, mood swings, overeating, and

excessive hair growth.

A comprehensive assessment was performed on symptoms three months

following heart transplantation in a study by Jalowiec, Grady, White-Williams, Fazekas,

Laff, Davidson-Bell, Kracht, & Wilson (1997). As part of a 10-year prospective design

study, 173 subjects completed a study booklet at three months after heart transplantation.

Seventy-nine percent were male and 21% were female. The results showed a significant

decrease in total symptom distress from before the heart transplant surgery to three

months following the surgery (t = 2.52, p = .013). Of the 23 symptoms that decreased

significantly, 11 were cardiopulmonary (i.e., shortness of breath on exertion, orthopnea,









palpitations, shortness of breath when sitting, coughing, chest pain, chest tightness,

wheezing, brady/tachycardia and pounding heart). Five symptoms were neuromuscular:

lethargy, fatigue, insomnia, weakness, and restlessness. Three were categorized as

emotional symptoms: anxiety, fear, and depression. Nausea and anorexia were the two

gastrointestinal symptoms that decreased. One genitourinary symptom that significantly

decreased was difficulty in sexual performance. It was found also in the study that some

symptoms persisted despite the heart transplant surgery. These symptoms were fatigue,

weakness, insomnia, lethargy, depression, anxiety, sexual problems, exertional shortness

of breath and tachycardia. Analysis of symptom distress showed that 10 symptoms (p =

.000) significantly increased in severity. These 10 symptoms were puffy face, hirsutism,

changes in facial and body features, acne, tremors, leg cramps, problems with taste,

feeling hungry and overeating.

Klonoff, Annechild, and Landrine (1994) investigated the impact of a variety of

psychological, physical and biological factors on exercise adherence. Twenty-three

women were recruited to participate in a free aerobics exercise program offered on a

university campus. The investigators found that a combination of five variables-height,

weight, physical symptoms, trait anxiety, and intensity of day-to-day hassles-best

predicted exercise adherence in their normal sample. These five reported variables

accounted for 73% of the variance in the number of exercise sessions attended by the

subjects and also correlated (r = .855) with the number of attended sessions. Physical

symptoms alone contributed 18.7% of the variance. The results of this study suggest that

individuals are likely to adhere to an exercise program if they are overweight, experience

several mild symptoms and are mildly anxious.









In a retrospective research study conducted by Dishman (1981), data from files on

362 males were retrieved that consisted of physiologic and morphologic variables, and

medical and exercise history. In reference to symptoms, Dishman reported a significant

relationship between coronary disease and adherence. He found that individuals in three

classification groups that experienced more physical symptoms associated with coronary

disease were more apt to be long-term adherers to an exercise program and attended more

days in the exercise program than did asymptomatic patients in two groups combined.

He concluded that individuals who experience more symptoms showed greater adherence

possibly in an attempt to alleviate or impede coronary artery disease and its associated

symptoms.

Summary

In summary, this chapter included a review of the theoretical framework, The

Theory of Planned Behavior. Seventeen independent variables were identified and

discussed in relation to the theoretical framework. The literature review presented all

study variables and relevant research studies. Chapter 3 describes the methodology for

the study.














CHAPTER 3
METHODOLOGY

The purpose of this study was to identify psychological, disease-related, physical,

situational and pre-operative factors and perceived social influences that are predictive of

adherence to exercise after heart transplantation. A secondary purpose was to identify the

combination of these factors that best predict adherence to exercise after heart

transplantation. Described in this chapter are the research design, human subjects

protection, sample, setting, major study variables, extraneous variables, measurement,

data collection procedure, data analysis, and limitations.

Research Design

The research design chosen for this study was a nonexperimental predictive

design that was appropriate for the purpose of identifying predictors of adherence to

exercise in heart transplant recipients. According to Bums and Grove (1997), predictive

research designs enable the investigator to predict the value of a dependent variable based

on the values obtained from other independent variables. Prediction attempts to explore

causal relationships between different variables. The predictive design in this study used

retrospective information to determine the relationships among the major study variables.

In other words, the proposed cause and effect has already occurred. Identifying

predictors of exercise adherence after heart transplantation will allow the development of

studies to evaluate specific treatment and exercise protocols for heart transplant recipients

with the goal of improving exercise adherence in this population.









Human Subjects Protection

Prior to implementing the research project, approval to conduct the study was

obtained from the University of Florida Human Subjects Committee, and the Human

Investigations Committee at Emory University where the study was conducted. Informed

consent (Appendix A) was obtained from each subject prior to enrolling them in the

study.

Confidentiality was maintained by coding the data obtained from each patient's

questionnaires with an identification number. The collected data were kept in a locked

file cabinet to further assure confidentiality. The data were collected for statistical

purposes only. Findings of the study were reported as group data. No individual patient

was identified.

Sample

The nonrandom convenience sample for this research study consisted of those

adult patients who had heart transplantation surgery six months prior to their participation

in this study. The subjects selected for this study were recruited from an accessible

patient population at the Transplant Outpatient Services Clinic at Emory University

Hospital. It was anticipated based on the number of heart transplant surgeries performed

during the previous years, this hospital clinic would have an adequate population of heart

transplant patients from which a sufficient sample size could be obtained.

Initially, a total of 40 subjects were deemed an adequate sample size to address

the research questions. This sample size was based on a formulation of 80% power, a

critical effect size of 0.50, a significance level of 0.05 for a two-tailed test, and realizing

at least 10 variables that would significantly explain the adherence. Due to death of









subjects, noncompliant behavior, and a decrease in the total number of heart transplant

surgeries performed, only 16 subjects were recruited to participate in this study.

Inclusion and Exclusion Criteria

Inclusion criteria for selection of subjects for this study included the following:

adult subjects 18 years or older of either sex, received and survived heart transplant

surgery, ability to read and write English, free of organ rejection, absence of significant

cognitive deficit, and six months post-operative heart transplant surgery. Exclusion

criteria for selection of patients for this study included the following: presently in a state

of organ rejection. Organ rejection was determined by endomyocardial biopsy as

performed by the transplant surgeon and/or cardiologist. Endomyocardial biopsy is

currently the gold standard for detection of heart rejection (Rourke, Droogan, & Ohler,

1999).

The inclusion and exclusion criteria were selected according to the following

rationale. Subjects must be 18 years or older in order to provide legal consent for

participation in the study and to preserve autonomy (Burs & Grove, 1997). Subjects

may be either male or female. Elimination of subjects based on gender limits the

potential for obtaining an adequate sample size at the proposed institution. Controversial

reports have been cited in the literature regarding the differences in gender in terms of

exercise adherence and are discussed further under the section on extraneous variables

(Emery, Hauck, & Blumenthal, 1992; King, Blair, Bild, Dishman, Dubbert, Marcus,

Oldridge, Paffenbarger, Powell, & Yeager, 1992). The population to be investigated in

this study was post-operative heart transplant recipients and the time frame for data

collection was set at six months post transplant. Therefore, subjects must have









successfully undergone heart transplant surgery and must be surviving six months later.

Six months was selected as the time period to study the subjects for the following

reasons: sternal precautions after surgery are implemented for approximately six weeks

and range-of-motion may be limited for 8-10 weeks (Keteyian & Brawner, 1997); the

highest incidence of acute rejection after surgery is within the first three months (Seifert,

1994), and approximately 50% of individuals participating in exercise programs dropout

within the first 3-6 months (Dishman, 1982). To complete the self-administered

questionnaires designed for this study, subjects must be able to read and write in the

English language, and be free of any cognitive deficits that would interfere with

completing the questionnaires. Subjects must also be free of organ rejection at the time

the study was conducted because this study measured their adherence to prescribed

exercise. If a subject was in a state of recent active organ rejection with abnormal cardiac

function, the physicians at the transplant clinic would routinely have all patients stop all

physical activity and exercise. Acute rejection usually is associated with left ventricular

diastolic dysfunction, loss of cardiac compliance, and reduced coronary vasodilatation

capacity, predisposing the heart to an increase in oxygen demand, thus, interfering with

the performance of exercise (Niset, Hermans, & Depelchin, 1991). Patients are allowed

to resume exercise when clinically stable and absent from rejection. The rationale for the

exclusion criteria of organ rejection is as previously stated.

Setting

This study was conducted at the Transplant Outpatient Services Clinic at Emory

University Hospital located in Atlanta, Georgia. This hospital was located in a

metropolitan city in the Southeastern United States with a population of approximately









3.5 million persons. Emory University Hospital is a 435-bed adult tertiary care facility

and teaching hospital and has the largest transplantation center in Georgia. The transplant

program began performing heart transplant surgery in 1988 and has performed a total of

370 surgeries. The average yearly number of heart transplants done at this center is 29.

In the previous two years, 29 were performed in 1999 and 28 in 2000. The one-year

survival rate after successful transplantation is 92%. The primary surgical technique used

at Emory is biatrial. The average age of the transplant recipient is 46.7 years old.

Yearly, approximately 78% are male and 22% are female.

The Transplant Outpatient Services Clinic at Emory University Hospital is located

on the second floor and consists of seven examination rooms, two stretcher bays, and an

area for five recliners. The clinic provides services of pre-transplant evaluation, post-

transplant follow-up care, ambulatory care and laboratory services. The patient

population consists primarily of an adult population who are transplant recipients of a

variety of solid organs including liver, pancreas, lung, heart, renal, and small bowel.

Definitions of Maior Study Variables

For purposes of this study, the major study variables were defined as follows:

Exercise Adherence

The major outcome variable is exercise adherence. Exercise adherence is

conceptualized as continuation and progression of daily performance of physical activity

after hospital discharge as prescribed. It is operationalized as the independent daily

performance of walking and/or bicycling and prescribed exercises after discharge from

the hospital.









Attitude Toward the Behavior Variables

Attitude is conceptualized as an expression of one's feelings or thinking. It is

operationalized as the expressed positive or negative evaluation of performing exercise as

measured by question 1 on the Adherence to Exercises Questionnaire II.

Motivation is conceptualized as the intention or inherent drive of the person to act

or perform a behavior. It is operationalized as the intention or inherent drive of the

person to perform exercise as measured by the total score on the Self-Motivation

Inventory Questionnaire.

Subjective Norm Variables

Perceived Social Influence is operationalized as the perceived degree of influence

others have regarding participation in exercise on a regular basis as measured by question

2 and 3 on the Adherence to Exercise Questionnaire II.

Perceived Behavioral Control Variables

Number of days on heart transplant waiting list is operationalized as the total

number of days between the initial listing on the UNOS heart transplant waiting list and

receiving the donor organ. Data on the number of days on the heart transplant waiting

list were obtained from the patient's heart transplant clinic record and were recorded in

answer to question 1 on the Adherence to Exercise Questionnaire III.

Functional status is conceptualized as the physical ability of the individual to

function in every day life. It is operationalized as the physical ability of the study

participant six months preceding heart transplant surgery and described as bedridden,

ambulating or exercising as measured by question 4 on the Adherence to Exercise

Questionnaire II.









New York Heart Association (NYHA) Classification is conceptualized as a

classification of heart disease based on the relationship between symptoms and the

amount of effort required to provoke those symptoms. It is operationalized as a

classification of heart disease: Class I is cardiac disease without resulting limitations of

physical activity; Class II is slight limitation of physical activity, comfortable at rest but

ordinary physical activity results in fatigue, palpitation, dyspnea, or anginal pain; Class

III is marked limitation in physical activity, comfortable at rest, but less than ordinary

physical activity causes fatigue, palpitation, dyspnea, or anginal pain; and Class IV is the

inability to carry out any physical activity without the discomfort or symptoms at rest.

(Braunwald, 1992). Data on classification of heart disease were obtained from the

patient's heart transplant clinic record and were recorded in answer to question 2 on the

Adherence to Exercise Questionnaire III.

Age is operationalized as the chronological age of the individual at the time of

study entry and was measured in years. Chronological age was obtained from the

patient's heart transplant clinic record and was recorded in answer to question 3 on the

Adherence to Exercise Questionnaire III.

Weight is operationalized as the weight of the individual at the time of study entry

and was measured in pounds. Weight was obtained from the patient's heart transplant

clinic record and was recorded on item 4 on the Adherence to Exercise Questionnaire Ill.

Ejection fraction is conceptualized as the percentage of preload volume ejected

from the left ventricle per heart beat. It is operationalized as the percentage of ventricular

diastolic volume ejected from the left ventricle with each beat as measured during cardiac

catheterization and expressed in percent. Data on ejection fraction were obtained from









the patient's heart transplant clinic record and recorded as the answer to question 5 on the

Adherence to Exercise Questionnaire III.

Comorbidity is conceptualized as the presence of other diseases or conditions. It

is operationalized as the total number of other diseases or conditions currently present

that may interfere with the ability to exercise. Data on cormorbidity were obtained from

the patient's heart transplant clinic record and recorded in answer to question 6 on the

Adherence to Exercise Questionnaire III.

Resting heart rate is operationalized as the heart rate of the individual taken at rest

and measured in beats per minute. Resting heart rate was obtained from the patient's

heart transplant clinic record and recorded as the answer to question 7 on the Adherence

to Exercise Questionnaire III.

Resting blood pressure is operationalized as the blood pressure of the individual

taken at rest and measured in mmHg on the sphygmomanometer. Resting blood pressure

was obtained from the patient's heart transplant clinic record and recorded as the answer

to question 8 on the Adherence to Exercise Questionnaire III.

Support system is conceptualized as the availability of others to provide positive

reinforcement regarding exercise. It is operationalized as family, friends and other

significant persons who directly give positive support to the study participant as

measured by question 5 on the Adherence to Exercise Questionnaire II.

Financial concerns is operationalized as the availability of personal finances to

pay for applicable exercise fees as measured by questions 6 an 7 on the Adherence to

Exercise Questionnaire II.









Convenience is operationalized as the relative ease or accessibility that is

experienced by the study participant in order to initiate exercise and measured in regard

to location and time as measured by questions 8, 9, 10, 11, 12, and 13 on the Adherence

to Exercise Questionnaire II.

Climate is operationalized as the climate or weather condition that exists in which

the study participant exercises and is classified as either outdoors or indoors and

measured as the degree in which it interferes with the performance of exercise as

measured by questions 14 an 15 on the Adherence to Exercise Questionnaire II.

Number of rejection episodes requiring pharmacological therapy since surgery is

operationalized as the total number of rejection episodes occurring since the surgical

procedure experienced by the study participant that were treated with immunosuppressive

medications. Data on the number of rejection episodes requiring pharmacological

therapy since surgery were obtained from the patient's heart transplant clinic record and

recorded in answer to question 9 on the Adherence to Exercise Questionnaire III.

Number of rejection episodes not requiring pharmacological therapy since surgery

is operationalized as the total number of rejection episodes occurring since the surgical

procedure experienced by the study participant that were not treated with

immunosuppressive medications. Data on the number of rejection episodes not requiring

pharmacological therapy since surgery were obtained from the patient's heart transplant

clinic record and recorded in answer to question 9 on the Adherence to Exercise

Questionnaire III.

Number of days since last rejection is operationalized as the total number of days

between the last day of the last rejection episode and the time of entry into the study.









Data on the number of days since last rejection were obtained from the patient's heart

transplant clinic record and recorded in answer to question 10 on the Adherence to

Exercise Questionnaire III.

Number of days of hospitalization after surgery is operationalized as the total

number of days of hospitalization from the day of surgery until the first discharge out of

the hospital. Data on the number of days of hospitalization after surgery were obtained

from the patient's heart transplant clinic record and recorded in answer to question 11 on

the Adherence to Exercise Questionnaire III.

Symptoms is conceptualized as the perception of an abnormal physical,

emotional, or cognitive change in the body or its function in relation to disease or

treatment. It is operationalized as the perception of changes in the body related to heart

disease, heart failure, heart transplantation, medication side effects and complications and

that can be categorized as psychological, neuromuscular, cardiopulmonary,

gastrointestinal, genitourinary or dermatological as measured by questions 16, 17, 18, 19,

20, 21,22, 23, and 24 on the Adherence to Exercise Questionnaire II.

Extraneous Variables

There are a number of variables that were not included in this study that may have

had the potential of impacting the study findings. These variables included gender,

education, smoking, heart transplant surgical technique, and previous participation in

exercise.

Gender may have had an impact on the study findings because a review of the

literature identified that women attain lower vigorous physical activity levels especially

at younger ages (Sallis, Hovell, & Hofstetter, 1992). However, with the addition of light









and moderate exercise, there is no difference between gender (King, Blair, Bild,

Dishman, Dubbert, Marcus, Oldridge, Paffenbarger, Powell, & Yeager, 1992). Gender

was not found to be a predictor of exercise adherence one year after participating in a

randomized exercise program (Emery, Hauck, & Blumenthal, 1992).

Education has been reported to be positively correlated with participation in

regular exercise in middle-aged adults (Rhodes, Martin, Taunton, Rhodes, Donnelly, &

Elliot, 1999). A primary reason cited for this positive correlation is that higher education

may increase the awareness of the associated health benefits of exercise and, also,

enhance the subjective norms related to exercise among those with greater education.

Mullineaux, Barnes, and Barnes (2001) also found that the individual who possessed

greater education was more likely to engage in physical activity to promote health. As a

result, education may have potentially impacted the findings of this study.

An inverse relationship has been shown to exist between smoking and the

performance of habitual exercise (Criqui, Wallace, Heiss, Mishkel, Schonfeld, & Jones,

1980). In addition, individuals who smoke are less likely to join exercise programs

(Massie & Shepard, 1971) and those that do participate in a structured program dropout

early (Oldridge, Wicks, Hanley, Sutton, & Jones, 1978). On the other hand, a past and

present history of smoking did not affect adherence and exercise patterns according to

Gale, Eckhoff, Mogel, and Rodnick (1984). For these reasons, smoking may have had

the potential to impact the findings of this study.

The heart transplant surgical technique refers to the technique that is used to

anastomose the donor heart to the recipient's coronary vessels and is identified as biatrial

or bicaval. Because of the technical difficulties associated with the biatrial technique and









benefits of the bicaval technique, as previously described, the surgical technique used

may have potentially impacted the findings of this study.

Previous participation in exercise may also have had an impact on the study

findings. Concerns for this factor are of importance because research studies have shown

that in supervised exercise programs, past participation in exercise was reported to be

positively correlated with present participation (Dishman, Sallis, & Orenstein, 1985).

Also reported in the literature is a strong relationship between sports played as a youth

and participation in vigorous activities as an adult (Dishman, Sallis, & Orenstein, 1985).

In contrast, attendance and adherence to an exercise program were not affected by

previous exercise patterns of subjects (Gale, Eckhoff, Mogel, & Rodnick, 1984).

Measurement

The instruments that were used in this study included the following: the

Adherence to Exercise Questionnaire I, the Adherence to Exercise Questionnaire II, the

Self-Motivation Inventory, the Adherence to Exercise Questionnaire III, and the

Demographic Data Sheet. The Adherence to Exercise Questionnaire I and II, and the

Self-Motivation Inventory were self-administered paper and pencil scaled questionnaires.

The Adherence to Exercise Questionnaire III and the Demographic Data Sheet were data

collection sheets for the investigator. Self-administered questionnaires were chosen for

this study for the following reasons: these instruments are the most widely used to

measure exercise adherence and can be administered with ease and low cost, a range of

ages can be used, all dimensions of exercise can be assessed that can generate the

examination of physical activity patterns, the behavior being studied is not altered, and

these measures are easily adapted to suit the needs of the population being study or









research question (Sallis & Saelens, 2000). It is reported in the literature that there is "no

gold standard" for the measurement of exercise adherence (Vitolins, Rand, Rapp, Ribisl,

& Sevick, 2000, p. 188S). Measuring adherence is extremely difficult because it is

defined loosely and very widely in the research literature (Martin & Dubbert, 1982;

Vitolins, Rand, Rapp, Ribisl, & Sevick, 2000).

Adherence to Exercise Questionnaire I

The Adherence to Exercise Questionnaire I (Appendix B) was designed to

measure exercise adherence, the major outcome variable, and was developed by the

investigator after a review of the literature. Numerous questionnaires exist that measure

physical activity subjectively and then use objective measures to assess for validation of

the questionnaire. Questions for the present study were derived from the following

instruments that assess physical activity and exercise: The Aerobics Center Longitudinal

Study Physical Activity Questionnaire (Kohl, Blair, Macera, & Kronenfeld, 1988);

Paffenbarger Physical Activity Questionnaire (Paffenbarger, Wing, & Hyde, 1978); and a

literature review by Wilson, Paffenbarger, Morris and Havlik (1986).

The following is a discussion on the reliability and validity measurements of each

of the two questionnaires. The Aerobics Center Longitudinal Study Physical Activity

Questionnaire is a self-administered questionnaire that assesses for leisure and household

activity based on three-month recall. There are 14 subsets to the first question that

pertain to the frequency, method, intensity, and duration of exercise. The methods of

exercise and physical activity assessed for are walking, stair climbing, jogging or

running, treadmill, bicycling, swimming laps, aerobic dance/calisthenics/floor exercise,

moderate sports, vigorous racquet sports, other vigorous sports or exercise involving









running, other activities, weight training, household activities, and lawn work and

gardening. The second question asks the respondent the number of times a week that is

spent engaged in vigorous physical activity that is long enough to work up a sweat.

Scoring of the questionnaire is done by assigning metabolic equivalent (MET) values to

the reported activities. One MET is the resting metabolic rate of an individual and it is

approximately equal to the resting oxygen consumption (3.5 ml kgl' min (Powers &

Howley, 1996). A total score is then derived by the addition of all MET values for each

of the activities.

Scale validity was reported by Kohl, Blair, Paffenbarger, Macera, and Kronenfeld

(1988). A maximal exercise treadmill stress test was used as the objective measure to

determine the contributions of the indices of the physical activity questionnaire in

predicting physical fitness. The variables in predicting physical fitness had a multiple

correlation coefficient of.65. The significant predictors of physical fitness were age (p =

-.34), an index of running, walking, and jogging participation (P = .31), and the response

on the frequency of sweating (P = .35). Validity of the questionnaire was also reported

by Oliveria, Kohl, Trichopoulos, and Blair (1996). In this study a significant correlation

(r= .41) was also found between baseline physical activity level and the objective

measure of an exercise treadmill test. Reports for scale reliability could not be found in

the literature.

The Paffenbarger Physical Activity Questionnaire is an interviewer or self-

administered questionnaire that assesses leisure-time activity with the recall of activity

based on either the previous week or previous year. It was initially designed to identify

activities associated with hypertensive cardiovascular disease in college alumni









(Paffenbarger, Wing, & Hyde, 1978). There are eight questions that pertain to the type,

frequency, intensity, and duration of exercise. Walking and stair climbing are two types

of exercise specifically addressed. Open-ended questions allow the respondent to report

their specific type of exercise they engage in regularly in terms of duration per year.

Activity for a 24-hour period is described based on five activity categories. Using

kilocalories is the primary method used for scoring walking, stair climbing and intensity

of activity in the questionnaire. Activity is also ranked by MET value to derive at

kilocalories expended. Scale reliability and validity were reported by Ainsworth, Leon,

Richardson, Jacobs, and Paffenbarger (1993). Self-reported data were validated with

direct and indirect measures that included cardiorespiratory fitness, body fatness, motion

detection, and physical activity records. Correlation coefficients ranged from .25 to .65

in men and 0.28 to 0.86 in women. Higher correlations were reported for total and

heavy-intensity physical activities (r = .34 -.69, p<.05). Lighter-intensity physical

activity and the Caltrac motion detector did not show a significant correlation (r<.35,

p>.05). Test-retest reliability at one month showed a high degree of scale stability (r =

72, p<.01) than it did at eight and nine months (r =.34, r = .43, p<.01, respectively).

The questions modified from the above instruments and contained in the final

version of the Adherence to Exercise Questionnaire I were developed specifically for this

study in order to identify exercise patterns of heart transplant recipients. The questions

were selected for simplicity and were based on the specific activities performed by the

subject during hospitalization after heart transplant surgery and the proposed home

program designed for each transplant recipient. The questionnaire consisted of eight

questions designed to determine how well patients adhered to their home exercise









program after heart transplant surgery. The questions pertained to the frequency,

duration, intensity, and specific type of exercise such as walking, bicycling, and stair

climbing. One question allowed the subject to identify other exercises performed that

were not listed on the questionnaire.

The first question asked if the subject exercises and was coded as yes or no. The

second question asked how many days per week exercise was performed and allowed the

subject to write in a number. The third question asked how many times exercise was

performed per week and also allowed the subject to write in the corresponding number.

The fourth question related to the number of minutes exercise was performed during each

session. This question also allowed the subject to write in a number. Questions 5, 6, and

7 related to a specific type of exercise, walking, bicycling or stair climbing, respectively,

and asked about the number of sessions performed per week and the average duration of

each session recorded in minutes. Questions 5 and 6 also investigated the number of

miles per session. Specifically to question 5, the pace of walking was coded on a five-

point scale where 1 equaled less than two miles per hour (mph), 2 equaled two mph, 3

equaled three mph, 4 equaled four mph, and 5 equaled more than four mph. An

additional question asked if the subject used a treadmill and was coded as yes or no.

Question 6 also coded on a five-point scale the pace at which the subject rode the bicycle

and was coded as follows: l=general leisure (less than ten mph), 2=light effort (10 -

11.9 mph), 3=moderate effort (12 13.9 mph), 4=vigorous effort (14 15.9 mph), and

5-racing (more than 16 mph). The final question on the Adherence to Exercise

Questionnaire I allowed the subject to identify any other type of exercise they were

performing regularly by writing in the name of the exercise. It also asked about the









number of times per week this exercise was performed and the duration in minutes per

session performed.

The other types of exercises that were performed and reported by the subjects

included situps, weight-lifting, stationary rowing, and water aerobics. These types of

activities were categorized as conditioning exercises and were reported as this category in

the results section.

Content validity of this questionnaire was supported by the following sources of

information: from a review of the literature addressing the measurement of exercise

adherence and by the Heart Transplant Coordinator and Physical Therapist assigned to

the transplant program who implemented the prescription for the physical rehabilitation

of the subject. A Content Validity Index (CVI) was determined for the Adherence to

Exercise Questionnaire I. The purpose for determining a Content Validity Index was to

judge and quantify the content validity of an instrument and its items (Lynn, 1986). A

panel of five experts was identified at Emory University School of Nursing and Emory

University Hospital. Three of the experts had substantial knowledge in instrument

construction and measurement. Two members of the panel were experts in the area of

exercise and physical therapy. Each member of the panel rated all eight items of the

questionnaire using a 4-point ordinal scale where 1 equaled irrelevant item, 2 equaled

slightly relevant, 3 equaled very relevant, and 4 equaled extremely relevant. An

additional question asked the experts to rate the entire instrument using the same 4-point

scale. Finally, the experts were asked to describe how the questionnaire items could be

improved. The mean CVI for each item was as follows: question one, 3.8; question two,

3.8; question three, 3.8; question four, 3.8; question five, 3.8; question six, 3.8; question









seven 3.4; question eight, 3.8; and overall opinion of the questionnaire, 3.4. A CVI rating

with a minimal score of 3 indicates item and/or questionnaire relevance as indicated by

the above scores. For the AEQ I, it can be concluded that the content of the questionnaire

and the questionnaire itself has been determined to be valid and measures the

performance of exercise. Suggested comments for the improvement of the questionnaire

by the experts were reflected in the subsequent revision of the questionnaire.

Because the Adherence to Exercise Questionnaire I was derived from two other

sources and a literature review as previously discussed, prior to implementing the

research study, a pilot study was conducted. The purposes of conducting the pilot study

were to test the clarity and readability of the questions, to ensure ease of administration,

and to verify the time for completion of the questionnaire. The pilot study was conducted

on six heart transplant recipients who were beyond six months from the date of their heart

transplant surgery. Five males and one female were conveniently selected on two

separate days at the Heart Transplant Clinic. The ages of these subjects ranged from 36 -

62 years and the subjects ranged from 8 months to 13 years post-operative heart

transplant surgery. The questionnaire was administered to the subjects under the same

conditions as previously discussed. The results of the pilot study demonstrated that the

questionnaire was adequate in allowing the subjects to report their exercise, the subjects

easily understood the questions, and the questionnaire was able to be completed in the

anticipated time frame.

Scale reliability was estimated using test-retest procedures to determine the

stability of the questionnaire across time. Thirteen (81.25%) of the population of this









study were retested after their initial test date. The average number of days between the

initial test and the retest was 67 days with a range of 35-110.

Adherence to Exercise Questionnaire II

The Adherence to Exercise Questionnaire II (Appendix C) was a second data

collection instrument that was developed by the investigator for the purpose of measuring

attitude toward exercising, perceived social influence, functional status, support system,

financial concerns, convenience, climate, and symptoms. It was designed after a review

of the literature was conducted. The format of the questionnaire required the subject to

respond to both Likert and semantic differential scales, as well as forced-choice

questions.

Attitude is one psychological factor that was measured and used a 7-point

semantic differential scale that asked the subject to respond to the phrase "my doing

exercise regularly is." There were eight sets of adjectives that were used to measure

attitude and they were as follows: punishing-rewarding, useful-useless, bad-good,

harmful-beneficial, wise-foolish, sad-happy, pleasant-unpleasant, and exciting-boring.

Measuring attitude was adopted from research conducted by Gatch and

Kendzierski (1990). They studied The Theory of Planned Behavior and its ability to

predict exercise intentions in 100 female college students. Their measurement of attitude

was constructed according to the theory developed by Ajzen and Fishbein. Although

three of the attitude measurement items were not significantly related to the other five

items, they did report internal consistency reliability with a Cronbach's alpha coefficient

of .79. Attitude is one of the psychological factors that measured the attitude toward the









behavior component of the theoretical framework and is measured by question I on the

Adherence to Exercise Questionnaire II.

The measurement of perceived social influence was derived from The Theory of

Planned Behavior (Ajzen, 1991) and was a direct measure of subjective norm and

normative beliefs as discussed earlier. It was assessed by having the subject respond to

the statement "most people who are important to me would approve-disapprove of my

doing exercise regularly" using a 7-point semantic differential scale ranging from not at

all to very much. A second question rated the subjects' motivation to comply with the

following question: "how much do you care whether other people approve or disapprove

of your performing exercise regularly ." It also used a 7-point semantic differential scale

where -=not at all and 7=very much. The product of these two ratings measured

subjective norm (Ajzen, 1991; Gatch & Kendzierski, 1990). Although subjective norm is

consistently measured in the research literature as suggested by Ajzen (1991), the

normative component has consistently been found to contribute insignificantly towards

the variance of exercise intention than the attitudinal component (Rhodes, Martin,

Taunton. Rhodes, Donnelly, & Elliot, 1999; Smith & Biddle, 1999). Courneya and

McAuley (1995) report that inconsistencies in the measurement of subjective norm exist

that may contribute to these insignificant findings. Perceived social influence is a

measurement of the subjective norm component of the theoretical framework and was

measured by questions 2 and 3 on the Adherence to Exercise Questionnaire II.

The pre-operative factor that was assessed is the functional status of the subject

six months preceding their heart transplant surgery, and was described as bedridden,

ambulating or exercising (Grady, Jalowiec, White-Williams, 1998; Riedinger, Dracup, &









Brecht, 2000; Salyer, Jewell, & Quigg, 1999). Pre-operative factors were a measurement

of the perceived behavioral control component of the theoretical framework and were

measured by question 4 on the Adherence to Exercise Questionnaire II.

Support system, financial concerns, convenience or access to exercise facilities,

and climate was measured and recorded as situational factors. One question was

designed to measure support system and asked the subject to respond to the following:

"do you get the kind of support from others that you need" and utilized a 5-point Likert

scale where 1 equaled not at all, 2 equaled not much, 3 equaled moderately, 4 equaled a

great deal, and 5 equaled completely. It was derived from the World Health Organization

Quality of Life Instrument (2000). Two questions were designed to measure financial

concerns. The first question assessed whether the subject paid a fee to exercise. The

second question assessed whether the subject had enough money to participate in exercise

and was designed using a 5-point Likert scale where 1 equaled never, 2 equaled seldom,

3 equaled quite often, 4 equaled very often, and 5 equaled always. Six questions were

designed to measure convenience or access to exercise facilities and assessed where the

subject exercised, if travel was involved in order to exercise, its accessibility, the

availability of time, and the convenience of the setting. All questions were formed

allowing the subject to respond to a 5-point Likert scale and was coded as follows:

l=never, 2=seldom, 3=quite often, 4=very often, and 5=always. Two questions were

devised that constituted the measurement of climate. The first question assessed whether

the subject exercised indoors or outdoors. The second question involved whether the

climate or weather prevented the subject from exercising and was formed using a 5-point

Likert scale identical to the convenience scale as above (Campbell & Etringer, 1999;









Gale, Eckhoff, Mogel, & Rodnick, 1984; Martin & Dubbert, 1982; Rogers, 1987).

Situational factors were a measurement of the perceived behavioral control component of

the theoretical framework and were measured by questions 5, 6, 7, 8, 9, 10, 11, 12, 13,

14, and 15 on the Adherence to Exercise Questionnaire II.

Symptoms were measured and recorded as disease-related factors. Eight

questions were designed to measure symptoms using a 5-point Likert scale where l=not

at all, 2=slightly, 3=moderately, 4=very, and 5=extremely. Eight symptoms were chosen

to be measured and were derived from previous research studies involving heart failure

patients and heart transplant recipients. The eight symptoms included fatigue, shortness

of breath, pain, dizziness, leg or feet swelling, tremors, insomnia and weakness. These

symptoms were cited in the literature to be common and frequent among those patients

who were diagnosed with heart disease and myocardial infarction, the recipient of a heart

transplant, and prescribed immunosuppressive therapy. (Cowan, Graham, & Cochrane,

1992; Grady, Jalowiec, Grusk, White-Williams, & Robinson, 1992; Jalowiec, Grady,

White-Williams, Fazekas, Laff, Davidson-Bell, Kracht, & Willson, 1997; Lough,

Lindsey, Shinn, & Stotts, 1985; Muirhead, Meyerowitz, Leedham, Eastbur, Merrill, &

Frist, 1992). Additionally, a final question allowed the respondent to list any other

symptoms that were experienced that interfered with the ability to exercise and that were

not previously mentioned. Disease-related factors were a measurement of the perceived

behavioral control component of the theoretical framework and were measured by

questions 16, 17, 18, 19, 20, 21, 22, 23, and 24 on the Adherence to Exercise

Questionnaire II.









Self-Motivation Inventory Questionnaire

Motivation is the second psychological factor that was measured, a component in

the attitude toward the behavior of the theoretical framework, and utilized the Self-

Motivation Inventory (Appendix D) developed by Dishman and Ickes (1981). It was a

40-item paper and pencil scale that assessed self-motivation. The items on the

questionnaire were scored using a five-point Likert scale that indicated the degree each

item was characteristic or uncharacteristic of the respondent's typical behavior. The

response choices were as follows: 1=very unlike me; 2=somewhat unlike me; 3=neither

like me nor unlike me; 4=somewhat like me; and 5=very much like me. The total

possible score ranged from 40 to 200 and consisted of 19 positive and 21 negative items.

The mid-point score for the questionnaire was 120 with those scoring above the mid-

point considered to be more self-motivated, and those scoring below 120 classified as less

self-motivated.

Scale reliability was reported by Dishman and Ickes to have a high internal

reliability with a Cronbach's alpha coefficient of .91. Repeated measurements at one

month to five months showed a high degree of scale stability (r's ranged from .86 to .92).

Construct validity was provided by the correlation of the SMI with the Thomas-Zander

Ego-Strength Scale (r = .63, p<.05) and a more reserved correlation with the Marlowe-

Crowne Social Desirability Scale (r =.36, p< .05). Discriminant validity was supported

by the minimal overlap with other motivational measures of social desirability, health

locus of control, and achievement tendency. Less than 10% of the variance in self-

motivation was explained in each measure. Diverse settings (habitual exercise programs,









preventive medicine and acute exercise) in which adherence to therapeutic exercise was

easily measured helped to demonstrate predictive validity of the SMI.

Adherence to Exercise Questionnaire III

The Adherence to Exercise Questionnaire III (Appendix E) was a data collection

sheet developed for use by the investigator. The purpose of this instrument was to record

data on the pre-operative, physical, and disease-related factors of this study.

The pre-operative factors that were assessed are as follows: the number of days

on the heart transplantation waiting list and the NYHA classification identified as either

class I, II, III, or IV (Grady, Jalowiec, White-Williams, 1998; Riedinger, Dracup &

Brecht, 2000; Salyer, Jewell, & Quigg, 1999). Pre-operative factors were a measurement

of the perceived behavioral control component of the theoretical framework and were

measured by questions 1 and 2 on the Adherence to Exercise Questionnaire III.

Measuring physical factors involved obtaining information about the subject's

age, weight, ejection fraction, existence of comorbidities, resting heart rate, and resting

blood pressure. For comorbidities, a total score was reported. These characteristics were

selected through a review of the literature (Dishman, 1994; Sallis, Hovell, & Hofstetter,

1992; Salyer, Jewell, & Quigg, 1999). Physical factors were a measurement of the

perceived behavioral control component of the theoretical framework and were measured

by questions 3, 4, 5, 6, 7, and 8 on the Adherence to Exercise Questionnaire III.

Disease-related factors were measured and reported as the number of total

rejection episodes since surgery, the number of rejection episodes requiring

pharmacological therapy and not requiring pharmacological therapy since surgery,

number of days since last rejection and the number of days of hospitalization after









surgery. These characteristics were selected through a review of the literature (Grady,

Haller, Grusk, & Corliss, 1990; Salyer, Jewell, & Quigg, 1999). Disease-related factors

were a measurement of the perceived behavioral control component of the theoretical

framework and were measured by questions 9, 10, and 11 on the Adherence to Exercise

Questionnaire III. Secondary information was obtained on the surgical technique

employed and indicated as either biatrial or bicaval technique (Cupples, 1997; Niset,

Hermans, & Depelchin, 1991; Salyer, Jewell, & Quigg, 1999).

Demographic Data Sheet: Sample Characteristics

The Demographic Data Sheet: Sample Characteristics (Appendix F) was the tool

used to collect descriptive data on each subject selected for the study. The instrument

contained demographic information about the subject's gender, ethnicity, marital status,

and educational level. Information was also obtained on the smoking history of the

subject, and their participation in exercise in the pre-operative period. These variables

represented extraneous variables that may have impacted the study findings as described

earlier. Information regarding the type of immunosuppressive medications currently

prescribed to the subject was also collected.

Data Collection Procedure

At the initiation of the study, the names of all patients who had heart transplant

surgery beginning with the preceding six months up to the present date were obtained

from the Clinic registry. Then, as each new heart transplant surgery was performed, that

patient's name and demographic data was obtained from the Clinic and the investigator

was notified by the Clinic the date and time of the patient's scheduled six-month clinic

visit. Each patient's chart was reviewed to identify whether he or she met the selection









criteria and was verified by the Heart Transplant Surgeon and/or Heart Transplant

Coordinator.

In this nonexperimental predictive study, the methods used for data collection

were the administration of questionnaires to the subjects and retrieval of data from the

patient's medical record as documented by the physician. Six months after heart

transplant surgery, patients were required to return to the transplant clinic for the

following scheduled activities: cardiac biopsy under echo guidance, the withdrawal of

blood for laboratory analysis, and office visit with the transplant surgeon and transplant

Coordinator. Those patients who met the criteria for inclusion in the study were

identified during the clinic visit. Explanation of the study was given to each subject and

informed consent was obtained. All subjects completed the Adherence to Exercise

Questionnaire I, the Adherence to Exercise Questionnaire II, and the Self-Motivation

Inventory Questionnaire. A quiet, private area in the clinic for completion of the

questionnaires was provided. Data for the Adherence to Exercise Questionnaire III was

obtained from the patient's medical record in the heart transplant clinic.

Data Analysis

All data analyses were performed using the Statistical Analysis System (SAS).

Descriptive statistics were used to obtain the summary measures for the data. It included

frequency distributions, percentage distributions, means, standard deviations, and ranges.

Regression and correlation analysis were used to address the research questions.









Limitations

The limitations identified for this study were as follows:

The first limitation of this study was that clinical generalizability may be limited

due to convenience sampling and the small sample size. However, theoretical

generalizability should not be limited. The small number of individuals receiving heart

transplants results in a small sample size and, therefore, may limit the strength of the

results and predictability of the study findings.

A second limitation of this study was that the majority of the data collected were

from self-reports. A requirement for self-reports is accurate recall of information by the

respondents. Self-reports may not be an appropriate instrument to use with all

individuals that may lead to either over or under reporting of information.

A third limitation was that an objective direct method to measure adherence to

exercise was not used. Direct methods of measuring exercise adherence provide more

accurate data by measuring physiological changes in physical capacity (Robison &

Rogers, 1994; Vitolins, Rand, Rapp, Ribisl, & Sevick, 2000).

Summary

This chapter identified the methodology of this research study. The design and

protection of human subjects was described. The convenience sample and selection

criteria including size and power analysis were stated. All variables for the study and

their measurement were explicitly described. Finally, the data collection procedure and

analysis of data were identified. Chapter 4 describes the results of the study and includes

subject characteristics, data related to research questions, and test-retest data.















CHAPTER 4
RESULTS

This chapter presents a description of the subject characteristics as well as the

results of the study according to the seven research questions. A summary of the study

results concludes the chapter.

Subject Characteristics

Data were collected on a total of 16 subjects to identify the pre-operative factors,

physical factors, psychological factors, situational factors, disease-related factors and

social influences that predicted adherence to exercise after heart transplantation. All

subjects met all selection criteria which consisted of adult subjects 18 years or older of

either sex, received and survived heart transplant surgery, ability to read and write

English, free of organ rejection, absence of significant cognitive deficit, and six months

post-operative heart transplant surgery.

Based on power analysis, the initial plan was to recruit a total of 40 subjects. The

final number of subjects who participated in this study was 16. There were several

reasons a larger sample size could not be obtained. There has been a decline in the

number of heart transplant surgeries performed at Emory University Hospital as a result

of the lack of donor organs available. There were a total of 18 subjects who met the

study criteria. Two subjects who underwent heart transplant surgery did not participate in

the study because they had died after the procedure.









Data obtained from the Demographic Data Sheet: Sample Characteristics

(Appendix F) as shown in Table 4-1 revealed 11 (68.75%) male and five (31.25%)

female subjects, and nine (56.25%) White and seven (43.75%) Non-White subjects

participated in the study. Eleven (68.75%) of the subjects were married and five

(31.25%) were nonmarried. One (6.25%) had an educational level of 9th grade or less,

three (18.75%) had some high school, five (31.25%) had a high school diploma, and

seven (43.75%) reported education at the college level. Twelve (75%) had a smoking

history, while four (25%) had never smoked. Finally, 10 (62.5%) of the subjects

participated in exercise in the pre-operative period and six (37.5%) did not participate in

exercise.

Table 4-2 presents secondary demographic variables, surgical technique and

immunosuppressive medications. The biatrial surgical technique was performed on 16

(100%) of the subjects who underwent heart transplant surgery. The surgeons at this

study site did not utilize the bicaval technique. The immunosuppressive medications that

were administered to the subjects post-operatively were Cyclosporine, Imuran,

Prednisone, and CellCept. Fifteen (93.75%) of the subjects were administered

cyclosporine, four (25%) received Imuran, 16 (100%) received Prednisone, 12 (75%) had

CellCept, and one (6.25%) received Prograf.

Summary Data on Exercise

This section presents summary data on adherence to exercise including the

frequency of exercise, type of exercise describing the average duration per session and

the frequency and total time of exercise per week for each individual exercise, average

exercise time, and the intensity of exercise.









Table 4-1
Sample Characteristics (N = 16)


Variable N %

Gender

Male 11 68.75

Female 5 31.25

Ethnicity

White 9 56.25

Non-White 7 43.75

Marital Status

Married 11 68.75

Nonmarried 5 31.25

Educational Level

9t or Less 1 6.25

Some High School 3 18.75

High School Diploma 5 31.25

College 7 43.75

Smoking

Yes 12 75.00

No 4 25.00

Pre-operative Exercise
Participation

Yes 10 62.50

No 6 37.50









Table 4-2
Secondary Variables (N =16)


Variable N %

Heart Transplant
Surgical Technique

Biatrial 16 100.00

Bicaval 00 0.00

Immunosuppressive
Medications

Cyclosporine 15 93.75

Imuran 4 25.00

Prednisone 16 100.00

CellCept 12 75.00

Prograf 1 6.25


Table 4-3 describes the frequency of exercise. Fifteen (93.75%) of the subjects

were actively involved in exercise six months after heart transplant surgery. One

(6.25%) of the subjects did not exercise. The average number of days of exercise

performed each week was 3.87 (2.02) with a range of 0-7. The average adherence rate,

or percent of average number of days exercised per week, was 55.35 (28.98) with a

range of 00 100. Fifteen (93.75%) of the subjects walked as part of their exercise

program; however, only seven (43.75%) used a treadmill. Bicycling was performed by

five (31.25%) of the subjects, stair climbing by two (12.50%), and conditioning exercise

by five (31.25%).









Table 4-3
Exercise Adherence (N = 16)


Variable N % M Range
SD

Exercise

Yes 15 93.75

No 1 6.25

Number of
Days Exercised Per Week 3.87 0-07
2.02

Adherence Rate (%) 55.35 00-100
28.98

Walking 15 93.75

Treadmill 7 43.75

Bicycling 5 31.25

Stair Climbing 2 12.50

Conditioning Exercise 5 31.25


The type and duration of exercise is described in Table 4-4. Walking was

performed an average duration of 48.59 (31.11) minutes per session, and a mean 4.09

(2.10) sessions per week, for an average total time of 243.51 (232.28) minutes per

week. The second type of exercise, bicycling, was performed an average duration of 7.15

(13.38) minutes per session, a mean 0.81 (1.19) sessions per week, for an average total

time of 18.03 (36.02) minutes per week. Stair climbing was performed an average

duration of 3.28 (9.51) minutes per session, a mean of 0.43 (1.19) sessions per week,









Table 4-4
Type ofExercise. Mean Duration Per Session, Frequency and Total Time of Exercise Per
Week (N= 16)


Type of Exercise Mean Duration Frequency Total Time
SD SD SD

Walking 48.59 4.09 243.51
31.11 t2.10 232.28

Bicycling 7.15 0.81 18.03
13.38 1.31 -36.02

Stair Climbing 3.28 0.43 11.48
9.51 1.19 33.31

Conditioning 14.06 1.25 68.75
Exercise 26.97 2.11 168.56


for an average total time of 11.48 (33.31) minutes per week. The last type of exercise,

conditioning exercise, was performed an average duration of 14.06 (26.97) minutes per

session, a mean of 1.25 (2.11) sessions per week, for an average total time of 68.75

(168.56) minutes per week.

Table 4-5 describes the average exercise time for all types of exercises combined.

The average number of minutes per session performed by all subjects combined was

73.09 (54.66) minutes. The average exercise time was 341.78 (380.24) minutes per

week by all subjects combined.

Table 4-5
Mean Exercise Time (N = 16)


Variable Minutes Per Minutes Per
Session (SD) Week (SD)

Exercise Time 73.09 (54.66) 341.78 (380.24)









The intensity of exercise performed is presented in Table 4-6. Walking was

classified as follows: light, 2 miles per hour (mph) or less; and moderate, 3 or more mph.

General leisure and light effort bicycling were classified as moderate intensity; and

moderate effort, vigorous effort, and racing were classified as vigorous intensity. Stair

climbing was classified as moderate intensity exercise only. The intensity of the

conditioning exercise was classified as light, moderate, or heavy according to the

performed exercise as reported by the subject.

Table 4-6
Intensity of Exercise (N = 16)

Type of Exercise Light Moderate Vigorous


N % N % N %

Walking 11 68.75 4 25.00

Bicycling 3 18.75 2 12.50

Stair Climbing 2 12.50

Conditioning
Exercise 5 31.25 2 12.50

Of the 15 subjects who walked, eleven (68.75%) of the subjects walked at a light

intensity pace, while four (25%) walked at a moderate intensity pace. Of the five who

bicycled, three (18.75%) reported bicycling at a moderate intensity, and two (12.50%)

exercised at a vigorous intensity. Of the two who stair climbed, both of the subjects

(12.50%) performed that activity at moderate intensity. Five subjects performed

additional conditioning exercises. All five (31.25%) performed moderate intensity

exercise such as water aerobics, light stationary rowing, and weight lifting, and two of the

five (12.50%) performed vigorous intensity conditioning exercise such as sit-ups

(calisthenics).









Summary Data on Major Study Variables

The major study variables were preoperative factors, physical factors,

psychological factors, situational factors, disease-related factors, and social influence.

Summary data on these variables are presented first. Data on psychological factors,

attitude and motivation, are shown in Table 4-7. The average score for Attitude was

48.25 (6.26), with a range of 35-56. The lowest possible score for the Attitude variable

is eight and the highest score possible is 56. The mean score for the Self-Motivation

Inventory was 154 (22.55) and ranged from 122-190.

Table 4-7
Psychological Factors (N = 16)

Score
Variable M SD Range

Attitude 48.25 6.26 35-56

Motivation 154.00 22.55 122-190



Results on the variable perceived social influence are shown in Table 4-8. The

average score describing the perceived degree of influence others had on the subjects

regarding participation in exercise was 18.81 ( 17.42), with a range of 1-49.

Table 4-8
Social Influence (N = 16)

Score
Variable M SD Range

Perceived Social
Influence 18.81 17.42 1-49









Data for two pre-operative variables, functional status and NYHA, are presented

in Table 4-9. Describing functional status, one (6.25%) subject reported being bedridden

pre-operatively, nine (56.25%) were ambulating, and six (37.50%) were exercising pre-

operatively. Using New York Heart Association (NYHA) classification, no subjects

were categorized as Class I, three (18.75%) were NYHA Class II, five (31.25%) were

NYHA Class III, and three (18.75%) were NYHA Class IV.

Table 4-9
Pre-operative Factors (N = 16)


Variable N %

Functional Status

Bedridden 1 6.25

Ambulating 9 56.25

Exercising 6 37.50

New York Heart
Association

Class I 0 00.00

Class II 3 18.75

Class III 5 31.25

Class IV 3 18.75


Data for pre-operative and physical factors are shown in Table 4-10. The average

number of days waiting for heart transplant surgery was 381.75 (531.10). A wide range

was seen among subjects from 4-1,840 days. Subjects were 19 66 years old and had a

mean age of 50.37(15.00) years. The mean weight of subjects was 186.93 (40.91)









pounds with a range of 111-255 pounds. Ejection fraction six months post-operatively

ranged from 30% to 65% with a mean of 61.33% (7.89). The average number of

comorbidities that were present after heart transplant surgery was 2.06 ( 1.69) with a

range of 0-5. The mean resting heart rate was 99.8 (16.05) beats per minute with a

range of 0-5; mean resting systolic blood pressure was 138.33 (19.76) mmHg with a

range of 110-180; and mean diastolic blood pressure was 85 (10.58) mmHg with a

range of 70-108.

Table 4-10
Pre-operative and Physical Factors (N = 16)


Variable M SD Range

Number of Days on
Waiting List 381.75 531.10 4-1840

Age 50.37 15.00 19-66

Weight 186.93 40.91 111-255

Ejection Fraction (%) 61.33 7.89 30-65

Comorbidities 2.06 1.69 00-05

Resting Heart Rate 99.80 16.05 60-119

Resting Systolic
Blood Pressure 138.33 19.76 110-180

Resting Diastolic
Blood Pressure 85.00 10.58 70-108

Data results for situational factors are presented in Table 4-11. The reported

mean for support system was 4.31 (0.70) with a range of 3-5. The mean is derived from

a 5-point Likert scale where 1 equaled not at all, 2 equaled not much, 3 equaled









moderately, 4 equaled a great deal, and 5 equaled completely. Three (18.25%) paid a fee

for exercise while 13 (81.25%) did not pay a fee. The mean for those subjects reporting

having enough money to participate in exercise was 2.73 (1.57) with a range of 1-5.

Mean scores for the variable convenience were as follows: exercise at home was 3.56

(1.45) with a range of 2-5; exercise in a health club/gym was 1.75 (1.39) with a range

of 1-5; travel to exercise was 2.00 (1.26) with a range of 1-5; accessibility was 3.93

(1.61) with a range of 1-5; enough time during the day to exercise was 4.18 (1.04)

with a range of 2-5; and setting convenient was 4.12 (1.25) with a range of 1-5.

Pertaining to the climate, nine (56.25%) exercised indoors, while seven (43.75%)

exercised outdoors. The mean score for those subjects indicating whether the climate

prevented them from exercising was 1.50 (0.51) with a range of 1-2. The means for

financial, convenience, and climate variables were derived from a 5-point Likert scale

where 1 equaled never, 2 equaled seldom, 3 equaled quite often, 4 equaled very often,

and 5 equaled always.

Data for disease-related factors are shown in Table 4-12. The average total

number of rejection episodes was 2.81 (1.68) with a range of 0-5 in the six-month

postoperative period. The average number of rejection episodes requiring

pharmacological therapy was 0.43 (0.72) with a range of 0-2; number of rejection

episodes not requiring pharmacological therapy was 2.37 (1.45) with a range of 0-5;

and the number of days since the last rejection episode was 89.43 (88.36) with a range

of 0-366. The average number of days of hospitalization after heart transplant surgery

was 18.18 (27.82) with a range of 7-111.









Table 4-11
Situational Factors (N = 16)

Variable

Support System

Financial

Pay Fee for Exercise

Yes
No

Enough Money to
Participate in Exercise

Convenience

Exercise at Home


Exercise in Health Club/Gym


Travel to Exercise


Accessibility


Time


Setting Convenient

Climate

Exercise

Indoors
Outdoors

Climate Prevents Exercise


N % M Range
SD
4.31 3-5
0.70


18.75
81.25


2.73
1.57


3.56
1.45

1.75
1.39

2.00
1.26

3.93
1.61

4.18
1.04

4.12
1.25


56.25
43.75


1.50
0.51