The health belief model: predicting compliance and dropout in cardiac rehabilitation. We investigated the health belief model and the health locus of control constructs as predictors of group membership (compliers or dropouts) with cardiac rehabilitation and whether they added predictive utility to routinely assessed patient demographics and health behaviors. Questionnaires were completed on entry into the study by 120 patients with coronary artery disease, and by the end of the 6 month program there were 58 compliers and 62 dropouts. Discriminant function analyses were carried out to determine prediction of group membership. The health belief model predicted group membership 64.6% of the time, explaining 5.2% of the variance. Demographics, health behaviors, and health belief model factors accounted for 21.1% of the variance between compliers and total dropouts with group membership correctly predicted 74.4% of the time; avoidable and unavoidable dropout was correctly predicted 84.2% of the time with 56.9% of the variance explained. Health locus of control did not distinguish between compliers and dropouts. The addition of the health belief model provided additional information about compliance with cardiac rehabilitation beyond that explained by demographic and health behavior variables alone, particularly when predicting avoidable/unavoidable dropout. 