Predicting self-efficacy using illness perception components: a patient survey.

Abstract

OBJECTIVES: To assess the measures of illness representation components in predicting measures of self-efficacy in patients with coronary heart disease. DESIGN: A longitudinal design was adopted with predictor variables and dependent variables (general self-efficacy, diet self-efficacy and exercise self-efficacy) measured twice while participants were in hospital and 9 months following discharge. Change scores of the predictor variables can be calculated and dependent variables at baseline can be controlled. METHOD: A cohort sample of 300 patients admitted to hospital with coronary heart disease were given the questionnaire measuring their illness perception (illness representation components: identity, consequences, timeline and control/cure and outcome expectation for diet and exercise); self-efficacy (general, diet and exercise self-efficacy measures), demographic and illness characteristics and attendance on a cardiac rehabilitation programme. The patients were asked to complete the questionnaire in hospital before discharge following their cardiac diagnosis, and again, 9 months later, when participants were expected to be functioning independently of any rehabilitation programme. RESULTS: Demographic and illness characteristics were found to have a more significant relationship with illness representation components than with specific self-efficacy. The relationship between illness representation components and specific self-efficacy changes overtime, consequence and timeline were significantly related to self-efficacy measures initially; however, symptom and control/cure were the variables that were significantly related to self-efficacy measures 9 months later. After statistically controlling individuals' baseline self-efficacy measures, demographic and illness characteristic effects, symptom and control/cure were found to make significant contributions to exercise and diet self-efficacy, respectively, 9 months later. CONCLUSION: A significant relationship exists between illness representation and self-efficacy. There is potential to integrate both approaches to the assessment of psychosocial factors to provide effective individualized care in cardiac rehabilitation.