Prediction of motivation and behavior change following health promotion: role of health beliefs, social support, and self-efficacy.

Dimensions of health beliefs (perceived risk of behavior and benefit of behavior change), social support (family and others' support for change), and self-efficacy (magnitude and strength) were examined in 215 patients undergoing a prospective trial of health promotion in a primary care medical practice. Discriminant analyses were performed to evaluate how well these dimensions predicted motivation for change and lifestyle behavior change. These relationships were examined for six lifestyle areas: cigarette smoking, dealing with stress, amount and type of food eaten, use of seat belts, and exercise habits. The analyses demonstrated a statistically and clinically significant prediction of motivation by one or more health belief and self-efficacy dimensions for most lifestyle areas. The strongest single predictors were perceived benefits and self-efficacy strength, which were each significant predictors of motivation in four lifestyle areas (P less than 0.05). Support dimensions, as measured, were not shown to have predictive value in most areas. Behavior change was poorly predicted by beliefs, support, and self-efficacy for most lifestyle areas. However, adding motivation to the discriminant function equation resulted in significant predictions in all six lifestyle areas (P less than 0.05), with an average correct classification rate of 71%. This finding strongly suggests that motivation is a very important intervening variable when evaluating health promotion and resulting behavior change.