Citation
Efficacy of a Peer Based Worksite Health Intervention on CVD Risk Factors in Firefighters: A Pilot Study

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Title:
Efficacy of a Peer Based Worksite Health Intervention on CVD Risk Factors in Firefighters: A Pilot Study
Creator:
Miller, Jordan
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Body fat ( jstor )
Control groups ( jstor )
Death ( jstor )
Exercise ( jstor )
Firefighting ( jstor )
Hand strength ( jstor )
Health promotion ( jstor )
Kale ( jstor )
Predisposing factors ( jstor )
Psychoeducational intervention ( jstor )
Cardiovascular system--Diseases
Cardiovascular system--Diseases--Prevention
Fire fighters
Fire fighters--Health and hygiene
Genre:
Undergraduate Honors Thesis

Notes

Abstract:
Cardiovascular disease (CVD) accounts for half of all the on duty fatalities and injuries in firefighters. Aerobic capacity, muscular fitness, body composition and physical activity are strong predictors of CVD in firefighters. The purpose of this study was to evaluate the efficacy of a peer-driven firefighter worksite health promotion intervention on improving aerobic capacity, muscular fitness, and body composition in firefighters failing to meet “fit for duty” requirements. Firefighters (n=144) received baseline health measures including submaximal aerobic capacity, body fat percentage, grip, arm, and leg strength, push-ups, curl-ups and a sit-and-reach test. Ten subjects were identified as not meeting “fit for duty” standards for firefighting and received a four month peer fitness intervention. Ten subjects were then matched by fitness levels from the remaining sample (n=134) and assigned to control conditions. Post-intervention testing was conducted on both groups for all health measures. Significant findings for those firefighters who received the intervention included submaximal aerobic capacity (p=.006), leg strength (p=.001), and the sit-and-reach test (p=.002). The preliminary findings suggests a peer mentor based approach to improving CVD risk factors in firefighters is efficacious and has important implications for worksite health promotion. ( en )
General Note:
Awarded Bachelor of Health Science; Graduated May 4, 2010 magna cum laude. Major: Health Science, Emphasis/Concentration: General Health Sciences
General Note:
Advisor: Christine Stopka
General Note:
College/School: College of Public Health & Health Professions
General Note:
Legacy honors title: Only abstract available from former Honors Program sponsored database.

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University of Florida
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University of Florida
Rights Management:
Copyright Jordan Miller. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.

Full Text

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1 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Abstract Cardiovascular disease (CVD) accounts for half of all the on duty fatalities and injuries in firefighters. Aerobic capacity, muscular fitness, body composition and physical activity are strong predictors of CVD in firefighters. The purpose of th is study wa s to evaluate the efficacy of a peer driven firefighter worksite health promotion intervention on improving aerobic requirements. Firefighters (n=144 ) received baseline health measures including submaximal aerobic capacity, body fat percentage, grip, arm, and leg strength, push ups, curl ups and a sit and firefighting and received a four month peer fitness intervention. Ten subjects were then matched by fitness levels from the remaining sample (n=134) and assigned to control conditions. Post intervention testing was conducted on both groups for all health measures. Sig nificant findings for those firefighters who received the intervention included submaxima l aerobic capacity (p=.006), leg strength (p=.001 ), and the sit and reach test (p=.002). The preliminary findings suggests a peer mentor based approach to improving C VD risk factors in firefighters is efficacious and has important implication s for worksite health promotion

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2 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Literature Review Cardiovascular disease (CVD) is the leading cause of on duty death and disability among firefighter populations, a ccounting for nearly half of all fatalities and injuries annually (Kales, 2007). In contrast, CVD events only account for 22% of police on duty deaths and disability, and 11% of deaths among on duty emergency medical s ervice workers (Macq uire, 2002). The d isproportionately high rate s of death and disability due to CVD among firefighters underscore an urgent need to reduce risk factors related to events of CVD in firefighters. Current research efforts are identifying the mechanisms of CVD in firefighters T his information is providing critical insight into the development implementation, and evaluation of effective health promotion programs to reduce CVD risk factors, death, and disability in firefighter populations (Elliot, 2007). The majority of CVD dea ths and disabilities in firefighters occur during strenuous physical exertion (Kales, 2007); suppressing a fire (36%), performing physically demanding non emergency duties (15%), responding to an alarm (13%), and engagi ng in physical training (12%) During these conditions, firefighters work at near maximal heart rates for prolonged period s of time under the stress of heavy equipment (Glendhill, 1992). Clinical physiological indicators based on lifestyle related behaviors are s ignificant predic tors for CV D in firefighters (Kales, 2003 ). Research shows physiological indicators include aerobic capacity, muscular conditioning, and body composition (Kales, 2007; Soteriades, 2004, Murphy, 2002). Surprisingly, most fire departments do not require firefighters to exercise or participate in health enhancing physical activity (PA) regularly (Kales, 1999). This is despite research showing firefighters from fire departments requiring physical training demonstrate higher rates of overall PA levels when compared to fire fighters from fire departments that do not require physical training (Green, 1991). Therefore, public health officials are advocating for interventions to

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3 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY adequately promote regular exercise i ncrease aerobic fitness and to improve physiological risk fact ors of CVD in firefighters (Rhea, 2004 Elliot 2004 & 2007). Despite widespread attempts to target worksites as a setting to pro mote increased PA there is little scientific evidence for the efficacy and effective ness of these interventions to increase P A or to improve physiological indicators related to CVD (Dishman, 1998;2005 ), especially in firefighter populations (Elliot, 2007). Efficacy is defined as the power to produce an effect. Effectiveness is the ability to have an intended or desired effect. Quantitative synthesis of the literature indicates most interventions are not theory driven do not include health promotion planning models, lack evidence based principles of behavior modification do not incorporate r obust experimental design s and often do no t include rigorous evaluation o f intervention effects (Kahn, 2002). Additionally, the majority of work site intervention efforts were not designed to address the broad range of influences over the performance of PA health behaviors. There is substant ial interest in the public health field for the development of health planning models guided by theory driven applications (Biddle, 2000). Theory driven models have important implications for work site health interventions for firefighters due to the uniqu e work structure inherent in the firefighter profess ion (Peterson, 1999; McLeary 199 8). The paramilitary style of policies regarding job performance, conduct, individual behavior, and team work predisposes the firefighter profession as a fully capable orga nization to institutionalize multi level based health promotion efforts. Studies show Social Cognitive Theory (SCT) holds promise for the development of effective health work site intervention targeting individual, social, environmental, and institutional policy behavior, social influences, and environment (reciprocal determinism) play a critical role in the

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4 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY performance of health behaviors. SCT rationalizes that so cial factors such as peer influences, role modeling of behaviors, and vicarious learning are significant mechanisms involved in PA behaviors. Specific Aims / Hypothesis / Research Questions Our long term objective wa s to implement an efficacious and effe ctive peer mentor based worksite health promotion program t o significantly reduc e the risk factors of CVD in firefighter populations by increasing PA in both the form of aerobic and muscular conditioning activities To achieve this goal, our research proje ct evaluate d the effectiveness of a Pee r Fitness Team health behavior i ntervention (PFTI) designed to improve the primary behavioral and physiological indicators for CVD in firefighters. Our working hypothesis wa s that firefighters not meeting fit for duty standards and participating in a four month PFTI will significantly improve aerobic capacity and muscular conditioning, while decreasing body fat percentage (body composition), compared to those in control conditions. Our hypothesis was tested by addressi ng two specific research questions: 1 .) Does participation in the PFTI cause an increase in aerobic capacity in firefighters? 2.) Does participation in the PFTI cause an increase in muscular conditioning? 3. ) Does participation in the PFTI help decrease bo dy composition ? Methods Participants Firefighters from Gainesville Fire Rescue (GFR) departments (n=144 ) completed a battery of annual physical fi tness assessments used to evaluate fit for duty standards Firefighters not meeti ng fit for duty standards (n =10 ) were recruited into the PFTI Borderline firefighters who did barely m et fit for duty standards serve d as a matched control group (n=10 ). Institutional Review Board approval was obtained and participants voluntar il y completed informed c onsent prior to the intervention.

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5 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Measures Baseline and follow up physical fitness health measures included: a submaximal aerobic capacity assessment body fat percentage, hand grip strength, arm and leg strength, push ups, abdominal static plank and a sit and reach te st. These measures were collected by a trained research team. A erobic capacity defined as the maximum amount of oxygen inhaled and carbon dioxide exhaled (VO 2 max ) was measur ed using the Gerkin protocol. The Gerkin involves a graded exercise stress test performed on a treadmill Participants complete d a standard protocol of increasing intensity over time until the participant reaches 85% of their maximum hear t rate (estimated by age). The time taken to reach 85% heart rate (Test Time) wa s then used in an equation {56.981 + (1.242 x test time) (0.805 x BMI)} to predict their VO 2 max The more time taken to achieve 85% max imal heart rate indicates healthier aerobic functioning, whereas a short er amount of time to reach 85% maximal heart rate is an indicato r of low aerobic health. Aerobic capacity is reported in ml/min/kg. Body fat percent age was estimated using a three point skin fold body composition assessment Hand grip, a rm and leg strength was measured as a static contraction with a dynamometer report ed in kilograms. Push ups and abdominal static plank s were measured by the total number of biomechanically sound repetitions completed. Flexibility was measured by using a sit and reach test and wa s reported in number of inches. Intervention Design The intervention group was exposed to a four month PFTI, based on SCT delivered by firefighters trained to be peer mentors promoting CVD health and fitness. Participants were classified as beginner, intermediate, or advanced based on their exercise experience Group workouts were then of cardiovascular and strength training. A manual containing variations of group workouts was also

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6 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY made available to all partic ipants in order to foster individual exercise training. Formati ve and process evaluations assess ed PFTI fidelity, reach, and level of firefighter participation. Statistical Analysis Plan : Data analysis was performed by using Statistical Packaging for th e Social Sciences (SPSS) version 17.0. A Wilcoxon matched pairs signed rank test and a paired sample T test assess ed differences in pre and post mean s of physical fitness measures within groups An i ndependent samples T test was used to asses s differences in pre and post means of physical fitness measures between groups. Results One hundred and forty four fire fighters completed the annual fit for duty physical fitness assessments. Ten firefighters did not meet fit for duty standards. 10 other firefighters w ere close to not meeting fit for duty standards and served as the control group. The average age of the se firefighters is 39 years old, 80% were male and 20% were female The independent samples T test revealed right hand grip strength as the only signi ficant difference between the two groups at baseline The control group had higher mean right hand grip strength at baseline. There were no mean differences in post testing fitness measures between the two groups. Data analysis with the Wilcoxin matched p airs signed rank test (Table 1), showed some health measures improved significantly from baseline to post testing for firefighters in the intervention group Significant findings included sub maximal aerobic capacity (p=.006), leg strength (p=.001 ) and the sit and reach test (p=.002). The paired samples T test (Table 2), also showed that aerobic capacity was increased significantly (p=.001) and right hand grip strength was decreased significantly (p=.0 4 3 ) in the intervention group There was no significant change in body fat percentage in the intervention group.

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7 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Within the control group, body fat percentage was significantly increased (p=.044) between pre and post tests. While these measures did change during the intervention, f indings for the grip strength, leg strength, push up, and abdominal static plank measures were not deemed statistically significant. The hypothesis that firefighters not meeting fit for duty standards and participating in a four month PFTI will significantly improve aerobic capacity an d muscular conditioning, while decreasing body fat percentage (body composition), compared to those in control conditions was partially met. This study investigated three research questions. These questions were, d oes participation in the PFTI cause an inc rease in aerobic capacity increase in muscular condition and a decrease in body composition? The first two aims of increasing aerobic capacity and muscular conditioning were met. While the body fat percentage did decrease slightly in the intervention gro up, it was not statistically significant. Discussion Increased aerobic capacity is perhaps the most important of the findings due to the relationship between VO 2 max and CVD prevention ic capacity reduces risk of CVD events (Peterso n et al. 2008). Positive changes in the other physical fitness activities, such as arm strength, and the sit and reach flexibility test are also important. Increasing performance in auxiliary exercises and overall physical fitness can also reduce the risk of CVD events (Harvey, Kraemer, Sharratt, & Hughson, 2007). Although participants in the intervention improved in arm strength and push up health measures they did not reach statistical significan ce These findings are important because these measures we re trending towards increased health and could potentially lead to a decreased risk of CVD events in firefighters Further testing would need to be done to validate the trajectory of these improvements. Th e results of this study provide efficacy for futu re worksite health site intervention efforts for firefighter populations due to the significant changes in health measures. This has important implications

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8 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY due to p revious worksite health promotion interventions showing mixed results (Dishman, 1998; 2005). The inconsistency of past worksite health intervention efforts is believed to be due to a lack of theor y driven approaches to the intervention design The strength of the current study is it involves role modeling positive health behaviors through Social C ognitive Theory. This approach allowed for a systematic methodology for reaching the target population. Results of this study should be interpreted in lieu of several limitations. First, the finding s of the study may be limited due to the small sample size. Additional studies of firefighters involving larger samples drawn from urban, rural, and suburban settings, along with more diverse demographic populations would improve external validity Although the sample was small, it did over represent female firefighters since 20% of the intervention population was female compared to the 8% of female firefighters who make up the overall firefighting work force. A second limitation was the lack of a randomized control group. All firefighters not meeting fit f or duty standards were recruited into the study, which precluded a true control group based on fit for duty criteria. To control for this limitation, the poorest performing firefighters on the fitness tests who did meet fit for duty standards provided a ma tched control group with those receiving the intervention. Future studies should randomize firefighters who do not meet fit for duty standards into either treatment or control groupings.

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9 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Table 1 Intervention Group Wilcoxin Matched Pairs Signed Rank Test Results Table 2 Intervention Group Paired Samples T Test Results Pre Intervention Mean Post Intervention Mean P Value Aerobic Capacity (VO 2 ) 37.70 39.982 .001 Sit and Reach (in.) 16.50 17.25 .555 Arm Strength (Kg) 42.60 41.39 .729 Leg Strength (Kg) 129.10 134.00 .913 Push Ups 21.80 20.70 .976 Body Fat Percentage 30.48 30.20 .229 Right Hand Grip Strength (Kg) 52.87 54.80 .043 Left Hand Grip Strength (Kg) 52 .5 3 52 80 .08 2 Pre Intervention Mean Post Intervention Mean P Value Aerob ic Capacity ( ml/min/kg ) 37.70 39.982 .006 Sit and Reach (in.) 16.50 17.25 .002 Arm Strength (Kg) 42.60 4 1.39 .013 Leg Strength (Kg) 129.10 134.00 .001 Push Ups 21.80 20.70 .060 Body Fat Percentage 30.48 30.20 .0 55 Right Hand Grip Strength (Kg) 52.87 54.80 .045 Left Hand Grip Strength (Kg) 52 .5 3 52 80 .086

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10 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY References Biddle, S., & Nigg, C. (2000). Theories of Exercise Behavior. International Journal of Sport Psychology, 31 290 304. Booth, S. (2001). Environmental and Societal Factors Affect Food Choice and Physical Activity: Rational, Influences, and Leverage Points. Nutrition Reviews, 59 (3), 21 39. Dishman, R. K., Motl, R. W., Sallis, J. F., Dunn, A. L., Birnbaum, A. S., Welk, G. J., et al. (2005). Self Management Strategies Mediate Self Efficacy and Physical Activity American Journal of Preventive Medicine 29 (1), 10 18. Activity Interventions. American Journal of Preventiv e Medicine, 15 (4), 344 361. Dodd, S. K. P. a. S. L. (1996). Total Fitness: Exercise, Nutrition, and Wellness Needham Heights, MA: Allyn and Bacon. Elliot, D., Goldberg, L., & Duncan, T. (2004). The PHLAME Firefighter's Study: Feasibility and Findings. A merican Journal of Health Behaviors, 28 (13 33), 13. Elliot, D., Goldberg, L., Kuelhl, K., Moe, E., Breger, R., & Pickering, M. (2007). The PHLAME (Promoting Healthy Lifestyles: Alternating Models' Effects) Firefighter Study: Outcomes of Two Models of Beh avior Change. Medicine & Science in Sports & Exercise, 28 (6), 706 719.

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11 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Emmons, K., Bess, H., Linnan, L., Rossi, J., & Abrams, D. (1994). Mechanisms in Multpile Risk Factor Interventions: Smoking, Physical Activity, and Dietary Fat Intake Among Manufac turing Workers. Journal of Preventative Medicine, 23 (481 489), 481. Geibe, R., Holder, J., Peeples, L., Kinney, A., Burress, J., & Kales, S. (2008). Predictors of On Duty Coronary Events in Male Firefighters in the United States. American Journal of Car diology Glanz, K., Rimer, B., & Lewis, F. (2002). Health Behavior and Health Education: Theory Reasearch and Practice (3rd ed.). San Francisco, CA. Glendhill, N., & Jamik, V. (1992). Characterization of the Physical Demands of Firefighting. Canadian Jou rnal of Sport Sciences, 17 (207 213), 207. Green, J., & Crouse, S. (1991). Mandatory Exercise and Heart Disease Risk in Firefighters: A Longitudinal Study. Occupational and Environmental Health, 63 51 55. Guidotti, T. (1995). Occupational Mortality Among Firefighters. Occupational and Environmental Health, 37 1348 1356. Harvey, D. G., Kraemer, J. L., Sharratt, M. T., & Hughson, R. L. (2007). Respiratory gas exchange and physiological demands during a fire fighter evaluation circuit in men and women European Journal of Applied Physiology, 103 89 98. Kales, S., Aldrich, J., & Polyhronopoulos, G. (1999). Correlates of Fitness for Duty in Hazardous Materials Firefighters. American Journal of Industrial Medicine, 36 618 629.

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12 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Kales, S., Steriades, E. & Christophi, C. (2003). Firefighters' Blood Pressure and Employment Status on Hazardous Materials Teams: A Prospective Study. Occupational and Environmental Health, 44 669 676. Kales, S., Steriades, E., Christophi, C., & Christiani, D. (2007). Emerge ncy Duties and Deaths from Heart Disease Among Firefighters in the United States. Macquire, B., Hunting, K., Smith, G., & Levick, N. (2002). Occupational Fatalities in Emergency Medical Services: A Hidden Crisis. Annals of Emergency Medicine, 40 625 632. Murphy, S., Bond, G., Beaton, R., Murphy, J., & Johnson, L. (2002). Lifestyle Practices and Occupational Stressors as Predictors of Health Outcomes in Urban Firefighters. International Journal of Stress Management, 9 (4), 311 327. Peterson, P., Magid D., Ross, C., Ho, M., Rumsfeld, J., Lauer, M., et al. (2008). Association of Exercise Capacity on Treadmill With Future Cardiac Events in Patients Referred for Exercise Testing. Archives of Internal Medicine, 168 (2), 174 179. Peterson, T., & Aldana, S. ( 1999). Improving Exercise Behavior: An Application of the Stages of Change Model in a Worksite Setting. American Journal of Health Promotion, 13 229 232. Rhea, M., Alvar, B., & Gray, R. (2004). Physical Fitness and Job Performance of Firefighters. Jo urnal of Strength and Conditioning Research, 1812 348 352.

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13 EFFICACY OF A PEER BASED WORKSITE HEALTH INTERVENTION ON CVD RISK FACTORS IN FIREFIGHTERS: A PILOT STUDY Soteriades, E., Hauser, R., Kawachi, I., Liarokapis, D., Christiani, D., & Kales, S. (2004). Obesity and Cardiovascular Disease Risk Factors in Firefighters: A Prospective Cohort Study. Obesity Reseacrh, 13 (10), 1756 1763. Wannamethee, S., & Shaper, A. (2001). Physical Acitivty in the Prevention of Cardiovascular Disease: An Epidemiological Perspective. Sports Medicine, 31 101 104.