Coronary heart disease (CHD) is the leading cause

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1 Journal of Cardiovascular Nursing Vol. 26, No. 5, pp 351Y358 x Copyright B 2011 Wolters Kluwer Health Lippincott Williams & Wilkins Systematic Review of Physical Activity Intervention Studies After Cardiac Rehabilitation Jo-Ana D. Chase, MN, ANP-BC Coronary heart disease significantly impacts the morbidity, mortality, and health care economy of our population. Enrollment into cardiac rehabilitation (CR) after cardiac events improves patient outcomes; however, physical activity (PA) behavior decreases significantly in the years following completion of CR. This article reviews the literature regarding interventions to maintain or increase PA after CR. Fourteen interventions studies from North America, Europe, Asia, and Australia used variations of cognitive and/or behavioral strategies. Women and older adults were underrepresented in the reviewed studies. Measurement of PA varied between studies and included self-report, objective pedometer or accelerometer data, or questionnaire format. Common cognitive interventions included self-efficacy enhancement measures, barrier management, and problem solving. Behavioral interventions included self-monitoring, prompting, goal setting, and feedback. Cognitive intervention studies reported inconsistent results, whereas behavioral studies and studies that used combinations of interventions reported more consistent, positive findings. More intervention studies, using rigorous designs and reliable measures of PA on larger, more diverse populations, are needed to improve the understanding of PA-related behavior change after completion of CR. KEY WORDS: cardiac rehabilitation, exercise, physical activity Coronary heart disease (CHD) is the leading cause of death worldwide, claiming approximately 7.2 million lives a year. 1 Within the United States, the estimated annual incidence of myocardial infarction (MI) is new and recurrent events. 2 Recurrence is highest within the first 5 years after the initial event. For the age group 40 to 69 years, the risk of recurrence is 16% for men and 22% for women. 2 The risk of recurrent MI at 70 years or older is even higher. 2,3 In addition to the sobering morbidity and mortality statistics, the diagnosis of CHD carries a heavy economic burden in the United States. The estimated direct and indirect cost of CHD for 2009 was $165.4 billion and in 2010 is projected to be $177.1 billion. 2,3 Developed in the 1960s, cardiac rehabilitation (CR) focuses on secondary prevention through risk factor modification. 4 Completion of CR that includes exercise training has been shown to decrease both cardiac and total mortality by 20% to 25% within 3 years Jo-Ana D. Chase, MN, ANP-BC Doctoral Student, University of Missouri Sinclair School of Nursing, Columbia. The author has no funding or conflicts of interest to disclose. Correspondence Jo-Ana D. Chase, MN, ANP-BC, 9419 Boatman Pier, Converse, TX (jdolojan76@gmail.com). DOI: /JCN.0b013e f00 after MI. 5,6 Furthermore, physical activity (PA) adherence beyond completion of phase 2 CR has also been shown to improve common risk factors of CHD, such as blood lipids and anthropometric measures. 7 Nevertheless, most patients do not continue PA levels comparable to those immediately after phase 2 CR, especially if they are not in a formal phase 3 program. 8 Existing literature in the area of PA maintenance after CR has not yet been synthesized to identify patterns and methodological strengths and weaknesses across studies. The purpose of this article was to systematically review the relevant literature to address the question of what interventions are helpful in maintaining PA in patients who have completed phase 2 CR, to suggest potential practice implications of findings and propose potential topics for further research. Methods The author conducted a literature search for intervention studies reported in English involving adult CHD patients using MEDLINE, PubMed, and CINAHL. Search terms were Bexercise,[Bexercise maintenance,[ Bphysical activity,[ Bphysical activity maintenance,[ Bcardiac rehabilitation,[ and Bphase 2 cardiac rehabilitation.[ Furthermore, the author completed author searches and ancestry searches from eligible studies. Studies with CHD subjects 30 years or older that were 351

2 352 Journal of Cardiovascular Nursing x September/October 2011 reported in English and completed between 1960 and 2010 were included. Methodological inclusion criteria were a 2-group design, PA behavior measurement as an outcome criteria, and at least 4-week follow-up after intervention. Randomization of subjects was not an inclusion criterion. Studies containing subjects attending CR for heart failure, valvular heart disease, or cardiac dysrhythmia were excluded. Results A total of 14 studies from Europe, North America, Australia, and Japan were retrieved and eligible for this review. The studies ranged in dates of publication from 2000 to They varied in research protocols, guiding theoretical framework, and intervention strategies. All studies contained 2-group designs, and only 1 study did not randomize its subjects. 9 Sample subjects were majority men except for 1 Australian study, in which all participants were women. 10 Sample sizes varied from 31 to 302 subjects. Sample ages ranged from 31 to 86 years, with a few studies reporting median ages in the 60s. 10,11 Patient follow-up ranged from 3 to 24 months. Measurement of PA also varied between studies, often using previously studied questionnaires, pedometer or accelerometer data, or self-report. In a few of the studies, factors such as exercise capacity, health-related quality of life, or overall cardiovascular risk were primary outcome measurements, not PA behavior. 10,12Y14 One study focused on more than PA behavior, including interventions on healthy diet as well. 12 Most studies used Bandura s 15 theoretical concept of self-efficacy or the Transtheoretical Model of behavior change of Prochaska et al 16 as primary theoretical frameworks. Researchers implemented interventions either during or following a phase 2 or equivalent national CR program. Interventions such as goal setting, prompting, feedback, and selfmonitoring were common behavioral strategies. 10,11,17Y19 Interventions involving problem solving, barrier management, and self-efficacy enhancement were common cognitive strategies. 9,13,14,20Y22 Two studies used a combination of cognitive and behavioral interventions. 12,23 One study used a variation of CR as its intervention. 24 Interventions During Phase 2 Cardiac Rehabilitation or Equivalent Table 1 shows the 6 studies that implemented interventions during phase 2 CR or equivalent national program. Three studies involved cognitive strategies. 13,14,20 Counseling sessions focusing on increasing self-efficacy, problem solving, and barrier management were inconsistently successful for promoting PA maintenance after completion of CR. Scholz and colleagues 20 found that subjects who attended 15-minute individualized planning sessions discussing action plans and barrier management for PA and submitted weekly diaries documenting action and coping plans participated in greater mean average minutes per week of PA at 4 and 12 months (4 months: mean, [SD, 109] min/wk; 12 months: mean, [SD, ] min/wk) after completion of CR in comparison to a standard care group (4 months: mean, [SD, 91.10] min/wk; 12 months: mean, [SD, 97.14] min/wk). Other researchers used small, groupcounseling sessions focused on problem-solving skills, barrier management, relapse prevention strategies, and self-efficacy enhancement, such as the CHANGE (Change Habits by Applying New Goals and Experiences) method. 13 Moore and colleagues 13 found that although all subjects had lower levels of PA 12 months after completion of CR, subjects who received the CHANGE intervention were more likely to continue PA behavior during that time period (log-rank test = 4.81, P =.02) as compared with control subjects. Implementation of cognitive strategies via counseling in a relatively younger population in Norway, however, did not produce similar results, as no differences in outcomes were noted between the control group and a group randomized to self-efficacy enhancement, problem solving, and outcome expectancy counseling. 14 Using the behavioral strategy of self-monitoring implemented during phase 2, Izawa et al 11 reported greater PA maintenance, with 100% of the experimental group continuing PA 12 months after acute MI in comparison to 80% of the control group. Furthermore, at baseline and 12 months, findings were significant for a higher mean number of steps taken daily in the experimental group (baseline: [SD, ] and [SD, 3310], respectively) 11 than in the control group ( [SD, ] and [SD, ], respectively). The above studies focused on interventions as adjunct to a center or hospital-based CR program. Smith and colleagues 24 suggested that entirely home-based CR may not only be comparable to hospital based programs and economically feasible, but also inherently promote post-cr PA maintenance by introducing the concept of community-based PA early. The researchers followed up subjects from a prior randomized controlled trial evaluating the success of a home-based versus hospital-based phase 2 CR. Habitual PA at 12 months, measured by Physical Activity Scale for the Elderly, was greater in the home-based group (mean, [SD, 99.4]) than the hospital based group (mean, 170 [SD, 89.2]), 24 suggesting that the impetus to maintain PA after CR may be in early adaptation of secondary prevention principles to patients home and community environments. Another study supports this concept. Carlson et al 23 implemented their intervention during the completion of phase 2 CR and into a phase 3 program focusing on transitioning patients into an off-site, long-term PA

3 Review of PA Intervention Studies After CR 353 TABLE 1 Interventions Administered During a Cardiac Rehabilitation (CR) Program Author/ Country Sample Theoretical Basis Type/Intervention Delivery/Dose PA Outcome Measures Results Carlson et al 23 /US Izawa et al 11 / Japan Moore et al 13 /US Scholz et al 20 / Germany Mildestvedt et al 14 / Norway Smith et al 24 / Canada n=80 Male: 82% Age = 35Y75 y; age differences between groups not reported n=45 Age = control median age 64.5 y; median age 63.9 y n = 250 Male = control 63.4%; median age 63.9 n = 198 Male = 82.3% Age = 58.5 (SD, 10.6) y; age differences between n = 176 Male = 78% Age = 56.0 (SD, 9.3) y; age differences between groups not reported n = 222 Male = hospital 79.4%; home 83.3% Age = hospital 63.4 (SD, 8.8); home 65.1 (SD, j9.0) Self-efficacy Cognitive and behavioral/ educational forums, support meetings, telephone follow-up; gradual restricted access to CR facility for exercise; log books Self-efficacy Behavioral/self-monitoring of body weight, objective PA, blood pressure, heart rate Multiple theories Cognitive/Change Habits by Applying New Goals and Experiences counseling Unstated Cognitive/individual planning session; diary of planning progress/coping strategies Theory of self-determination Cognitive/individual counseling sessions; follow-up phone counseling Unstated Not applicable/prior RCT studying home- or hospital-based CR 6 mo Weekly forum, meetings, phone calls at weeks 6Y25 of CR; exercise 1Y2 times/wk on site only; weekly logging of exercise Self-monitoring taught phase 2 CR; continued after completion of CR but at unknown intervals Three 90-min sessions weekly during 3 wk of CR; 2 sessions held at 1 and 2 mo after CR 15-min individual planning session last week of CR; weekly diary 6 wk to complete and return by mail Two counseling sessions during CR; phone calls at 6 and 24 mo Instrument: frequency/ duration documented weekly by log book or witness on-site session Follow-up: 6 mo after CR Instrument: stages-ofchange model of exercise behavior; pedometer data 1 wk Follow-up: 6 mo after (12 mo after MI) Instrument: exercise measured using portable wristwatch heart rate monitor; activity diaries Instrument: International Physical Activity Questionnaire Follow-up: 2nd week of rehabilitation, 4 and 12 mo after CR Instrument: exercise composite score; physical capacity scores Follow-up: completion of CR, 6 and 24 mo after CR None Instrument: Physical Activity Scale for the Elderly Follow-up: at completion of CR and 12 mo after CR Greater off-site exercise time, total exercise time, and lower dropout rate in 100% of continued physical activity; mean no. of steps higher in Intervention felt to be effective in reducing probability of stopping physical activity in year following CR Average min/wk of PA higher in at 4 and 12 mo No difference in outcomes for exercise score, physical capacity, or exercise intensity Home reported higher levels of habitual PA at 12 mo Abbreviations: MI, myocardial infarction; PA, physical activity; RCT, randomized controlled trial.

4 354 Journal of Cardiovascular Nursing x September/October 2011 routine. Researchers noted that in the last 3 months of follow-up, the modified protocol group s total PA amount was 23% higher than that of the control group (P =.03). 23 Interventions Following Phase 2 Cardiac Rehabilitation or Equivalent Table 2 displays 8 studies that implemented interventions following phase 2 CR or equivalent. Three studies used cognitive strategies such as barrier management techniques, problem solving, and motivational counseling. Two separate studies in the United Kingdom applied exercise consultation interventions after completion of a phase 2 program. Researchers found that a single 30-minute session of exercise consultation focusing on barrier management techniques and relapse prevention contributed to a median increase change in minutes of activity 4 weeks after implementation. 21 Another study applied similar, but more frequent, exercise consultations involving barrier management, motivational counseling, and outcomes expectancy. Results showed borderline significance, with 85% of the experimental group and 67% of the control group regularly active at 12 months (# 2 = 3.0, P =.08). 22 Again, cognitive interventions were not consistently successful. Yates and colleagues 9 implemented booster sessions guided by Bandura s 15 concept of self-efficacy at 3 and 9 weeks after discharge from a cardiac rehabilitation program. These interventions were administered person-toperson or by phone. Follow-up evaluation at discharge from phase 2 at 3 and 6 months thereafter showed no significant differences in frequency and duration of PA in terms of sessions per week between the control group and the group receiving the booster session by phone or by in-person delivery. 9 Four studies implemented behavioral strategies such as self-monitoring, goal setting, and feedback. Selfmonitoring via documentation in an exercise log or activity diary was very successful in promoting PA maintenance after completion of CR. 10,17Y19 These logs or diaries typically involved descriptions of activities and exercise, documentation of progress toward individual goals, and self-feedback. Within these studies, some researchers incorporated multiple behavioral interventions. In conjunction with self-monitoring, Johnson et al 10 randomized an to receive a 12-week home walking program after completion of CR with a set goal of walking at least 30 minutes 3 times a week. At 3, 6, and 12 months after cessation of CR, a larger percentage of intervention subjects reported more regular PA in comparison to their usual care counterparts. 10 Butler and colleagues 19 not only used self-monitoring and goal setting as interventions, but also incorporated regular telephone based feedback. The randomized intervention group of this Australian study received a pedometer with instructions for use and how to track steps. At 6 weeks, there was a positive change in total PA sessions relative to controls (mean effect size, 0.33; P =.002), 19 walking minutes (mean effect size, j0.54; P =.013), and walking sessions (mean effect size, 0.78; P G.001). Results persisted at 6 months as well, with improvement in total PA session (mean effect size, 0.52; P =.016), 19 PA activity minutes (mean effect size, 0.43; P =.044), and walking sessions (mean effect size, 0.46; P =.035) compared with controls. The above studies suggest that a combination of behavioral interventions may improve PA maintenance in the long term after completion of CR. One study used a combination of cognitive and behavioral interventions targeted toward diet and exercise. In the Canadian Extensive Lifestyle Management Intervention (ELMI), researchers randomized patients who had completed a 16-week traditional CR program into a usual care group, receiving a 1-year outcome assessment, and the ELMI group, which was given monthly interventions in the form of supervised exercise sessions, feedback sessions, counseling, or phone calls. 12 The ELMI subjects continued modified CR sessions ending by the third month of the study, received extensive exercise and diet counseling, documented their progress in a log book, and were assessed periodically with lifestyle and risk factor reduction feedback, an exercise stress test at 6 months, and in-person counseling. Physical activity was determined by a 4-week modified Minnesota Leisure Time Physical Activity Questionnaire, translating amount of PA into kilocalories per week expended. The researchers used complex and extensive interventions addressing multifactorial aspects of change in a variety of behaviors such as PA and diet; however, study findings were not specifically significant for PA behavior change. Methodological Issues There were some methodological issues noted within the studies. Almost half of the studies contained small sample sizes with fewer than 100 participants. 9,11,19,21Y23 Furthermore, samples were relatively homogeneous with women and older adults not adequately represented in most of the sample populations. Only 1 study reported the racial demographics of subjects. 13 Sample follow-up was relatively short overall, with the longest time period being 2 years. 14 There was considerable variety measuring PA behavior. In several of the studies, PA measurement was by nation-specific questionnaires. 12,14,17,19Y21,24 One study measured PA behavior by diary entries. 18 Two studies used questionnaire or subjective report,

5 Review of PA Intervention Studies After CR 355 TABLE 2 Interventions Administered After Completion of a Cardiac Rehabilitation (CR) Program Author Sample Theoretical Basis Type/Intervention Delivery/Dose Outcome Measure Results Yates et al 9 /US Sniehotta et al 17 / Germany Arrigo et al 18 / Switzerland Hughes et al 21 /UK Lear et al 12 / Canada Hughes et al 22 /UK Johnson et al 10 / Australia Butler et al 19 / Australia n=64 Male: 69% Age = 40Y86 y ; age differences between n = 240 Male: 81.5% Age = 31Y80 y; age differences between n = 228 Male = 85% Ages = 61 (SD, 10) y; age differences between n=31 Male = 65% Ages = control 61.5 (SD, 8.4) y/experimental 63.3 (SD, 6.9) y n = 302 Male = 83% Ages = control 63.4 (SD, 10.2) y/intervention 64.8 (SD, 8.8) y n=72 Male = 77% Ages = 60 (SD, 10.7) y; age differences between n = 154 Male = 0% Age = control median age 64 y; intervention median age 62 y n=72 Male = 75% Ages = control 64.5 (SD, 11.2) y; intervention 63.0 (SD, 10.4) y Self-efficacy Cognitive/telephone or in-person counseling Selfregulation model Behavioral/received weekly diaries to log progress, diaries contained reminders of goals Unstated Behavioral/diary to describe PA frequency, duration; periodic group exercise/ counseling session TTM Cognitive/exercise consultation based on TTM TTM Cognitive and behavioral/log book; supervised exercise sessions, lifestyle and exercise counseling, telephone follow-up, feedback assessments TTM Cognitive/exercise consultation, telephone support based on TTM Unstated Behavioral/walking program after completion of outpatient cardiac rehabilitation; activity logs Self-efficacy Behavioral/pedometer; step calendar for recording; telephone consultation 3 and 9 wk after CR Instrument: questionnaire of adherence to program of aerobic activity for 920min Q3 times a wk Follow-up: at completion of phase 2 CR, 3 mo, 6 mo, via mailed surveys Diaries mailed out weekly for 6 wk Session every 3 mo; diaries collected at that time Instrument: Kaiser PA survey Follow-up: 2 and 4 mo after CR Instrument: PA = being active to noticeably increase pulse rate and breathing Q3 times per wk for Q30 min Follow-up: 1 y Single dose; 30 min Instrument: Scottish PA questionnaire Follow-up: 4 wk Monthly 12 mo Instrument: 4-wk modified Minnesota Leisure Time Physical Activity questionnaire Follow-up: 1 y Consultation at completion of CR and 6 mo; support call 3 mo after consultation Oriented to 12-wk program by 30-min phone call; daily activity log Daily record of steps 6 wk; telephone calls at 1 wk after instruction, and 3, 12, and 18 wk Instrument: 7-d recall; accelerometer data during all waking hours for 7 d Follow-up: completion of CR, 6 and 12 mo after CR Instrument: stages-of-change model of exercise behavior Follow-up: 3, 6, and 12 mo Instrument: Active Australia survey Follow-up: 6 wk and 6 mo No significant differences in outcomes between groups Greater general PA by report in intervention group Greater number of physically active subjects in Increase median minutes per week in intervention group No significant findings between groups Increase in mean physical activity time at measured intervals in Percentage of subjects engaging in regular physical activity by self-report higher in Total PA sessions, walking minutes, and walking sessions higher in Abbreviations: PA, physical activity; TTM, Transtheoretical Model.

6 356 Journal of Cardiovascular Nursing x September/October 2011 coded by the researchers into Transtheoretical Model stages of change, then translated into levels of PA. 10,11 Objective PA behavior data collected by pedometer or accelerometer were for specified time periods dictated by the researchers and told to subjects, who were thus aware of timing of PA behavior data collection. 11,13,22 Discussion This systematic review documented a variety of interventions to promote PA behavior after CR. The question of what interventions are helpful in maintaining PA in patients who have completed phase 2 CR has been addressed. Studies reporting cognitive-only interventions, such as barrier management, problem solving, and enhancement of self-efficacy, were inconsistently successful. Combinations of different behavioral interventions were more consistently successful. Self-monitoring was the most common form of behavioral intervention in these studies. Other behavioral interventions included goal setting, feedback, and prompting. These findings suggest that behavioral strategies and combinations of behavioral strategies are more successful in PA behavior change than cognitive strategies. Conn et al 25 reported similar findings in a meta-analysis reviewing interventions to increase PA in chronically ill adults. Of note, 1 study in this review addressed interventions to promote both a healthy diet and PA behavior. Results did not demonstrate significant differences for PA behavior between control and s. 12 Although this is a single study within the review, it is important to note that, in the literature, interventions directed toward PA behavior only have been more successful at changing PA adherence than those directed toward multiple behavior changes concurrently. 25,26 Given the findings of this review, some practice implications may include focusing on 1 behavior change at a time and implementing combinations of behavioral interventions when promoting lifestyle modifications with patients who have completed a CR program. For example, in terms of PA behavior, using self-monitoring in the form of an activity log and objective feedback in the form of periodic exercise stress testing may yield greater success when working with patients to increase PA adherence. Studies used varied PA measures. Some studies used subjective quantification through self-reports, descriptive activity logs, and questionnaires. Accurate PA quantification may have been biased by participant subjectivity and researcher coding. Moreover, a recent study reported considerable lack of standardization, construct and content validity in 52 commonly used questionnaires to measure adult PA. 27 Others utilized objective data through pedometers or accelerometers. However, there are some limitations using these instruments as objective measurements of PA behavior, such as compliance with use and the lack of ability to measure energy expenditure in similar activities of varying intensities (eg, walking vs walking with weights). 28,29 Objective data were usually collected over a specified time frame. Subjects were aware that their PA was being evaluated for that period, which may have influenced their PA behavior during data collection. Measurements of PA behavior are diverse, and there has been much literature on the best method to quantify PA. Future intervention studies addressing PA behavior change should account for areas of bias and instrument validity to avoid methodological limitations. Because the studies were from different countries, there was no consistent CR protocol. In the German studies, for example, CR was an inpatient, 4-week program. 17,20 In Norway, the length of subjects CR depended on diagnosis of MI or coronary artery bypass graft (CABG) surgery. 14 Within the United States, phase 1 CR occurs in inpatients, after the initial cardiac event such as MI or CABG. Phase 2 occurs on an outpatient basis and usually lasts 3 to 6 months. Phase 3 is considered individual maintenance of CR, generally outside the rehabilitation facility. Without standardization among CR length, location, and content, it is difficult to compare true efficacy of interventions, as results may be influenced by the variety of CR programs globally. Thus, to have a better understanding of PA behavior change interventions after CR in the United States, more research within this country is needed. Racial demographics and socioeconomic status were not consistently addressed in these studies. Moreover, women and older adults were underrepresented. This finding is consistent with general CR participation after MI in the community. 30 Witt et al 30 found that women were 55% less likely to participate in CR after MI. Moreover, people 70 years or older were 77% less likely to participate in comparison to those 60 years or younger. Research focusing on women, minority, or lower socioeconomic groups is needed to address PA behavior after CR in these often underrepresented, atrisk populations. Also, research focused on interventions to improve PA maintenance in the growing cardiac older adult population would be both valuable and challenging. The older adult population may need age- or cohort-specific modifications, as interventions would need to be tailored not only to cognitive and developmental status and comorbidities, but also to comfort levels with technology, such as pedometers and technology-mediated communication. Limitations of this systematic review primarily involve study selection. Unpublished works, such as dissertations, theses, or presentation reports, may have contained eligible data, but were not included in this

7 Review of PA Intervention Studies After CR 357 Clinical Pearls h Physical activity levels achieved during cardiac rehabilitation decrease after completion of the program. h Patients completing cardiac rehabilitation may be able to continue engaging in physical activity through implementation of behavioral interventions, such as self-monitoring with an activity log or a pedometer, prompting during regular clinic visits, and objective feedback, such as periodic stress testing. review. Furthermore, studies involving other cardiovascular subjects, such as CR patients with heart failure, valvular disease, or peripheral vascular disease, would increase the number and heterogeneity of studies for review. In clinical practice, cardiac patients often have more than 1 cardiovascular diagnosis. Given the diversity of studies and small sample, too few studies were retrieved to conduct a meta-analysis on primary reports. Research pertaining to PA behavior interventions in patients who have completed CR and have multiple cardiovascular diagnoses is needed to assist clinicians in addressing best interventional strategies in their practice. This systematic review has examined interventions to promote PA behavior after CR in CHD patients and has proposed areas of further research and practice implications. Coronary heart disease significantly impacts the morbidity, mortality, and health care economy of our population. When primary prevention fails to deter complications of CHD such as MI, CABG, or subsequent heart failure, secondary prevention in the form of CR may help recover patients quality of life and reduce the risk of recurrence. Once a patient has completed CR, however, sustaining PA adherence and appropriate lifestyle modifications is essential to maintaining cardiovascular risk reduction. Clinicians are in a unique position to educate and support patients PA behavior. 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