Correlates of compliance in a randomized exercise trial in myocardial infarction patients

Purpose: Exercise-based rehabilitation programs have been associated with d ecreased morbidity and mortality after myocardial infarction. Unfortunately , attendance is often poor, and information is limited regarding predictors of long-term compliance to such programs. This study examined factors asso ciated with exercise session compliance over 3 yr in male myocardial infarc tion (MI) survivors. Methods: Subjects were participants in the National Ex ercise and Heart Disease Project, a 3-yr (1976-1979) multicenter, randomize d clinical trial (N = 651); 308 men, 30-64 yr of age, were randomized to th e exercise treatment group, that met three times/week throughout the study. Compliance was defined as the number of sessions attended/number of sessio ns conducted. Patient characteristics at enrollment were considered as poss ible predictors of compliance. Results: Compliance decreased as time since enrollment increased with the largest decrease observed after the first 8 w k. Compliance correlated positively with exercise test measures [last compl eted stage (r = 0.17, P < 0.01), peak heart rate (r = 0.11, P = 0.06)], hig h density lipoprotein (HDL) cholesterol (r = 0.15, P = 0.10), age (r = 0.11 , P = 0.07), and inversely with body mass index (r = -0.19. P = 0.001). sum of three skinfolds (r = -0.15, P < 0.01), total cholesterol (r = -0.18, P < 0.01), triglycerides (r = -0.16, P < 0.01), and depression (r = -0.09, P < 0.11). Current smokers were less compliant than former and nonsmokers (r = -0.21. P < 0.001). The correlations with last completed stage, BMI, skinf olds, total cholesterol, and smoking status were statistically significant. The model explained 22.2% of the variance in compliance (r(2) = 0.222). Ba seline work capacity was among the most consistent predictors of early and late compliance. Conclusion: Compliance decreased over time. Men already at high risk for repeat events due to elevated risk factors were less complia nt. These findings have important clinical implications regarding screening , intervention, and participation in potential cardiac rehabilitation progr am dropouts.