Abstract
BACKGROUND AND AIM: The present study aimed to develop and psychometrically evaluate the exercise self-efficacy tool within the Health Action Process Approach (HAPA) framework among heart failure patients undergoing cardiac rehabilitation. METHODS: This study assessed 205 patients who had suffered heart attacks at the Shahid Chamran Cardiac Rehabilitation Center of Isfahan. Exploratory factor analysis (EFA) was employed to evaluate the construct. Internal reliability was determined using Cronbach's alpha. Additionally, external reliability was measured through a test-retest approach. RESULTS: EFA identified four factors within the self-efficacy questions (task self-efficacy 1, task self-efficacy 2, coping self-efficacy, and recovery self-efficacy), which accounted for 70.1% of the total variance explained. The Cronbach's alpha coefficients were as follows: 0.836 for the first factor, 0.896 for the second factor, 0.921 for the third factor, 0.914 for the fourth factor, and 0.9 for the overall instrument. The intra-class correlation coefficient was 0.901 for the first factor, 0.887 for the second factor, 0.826 for the third factor, and 0.885 for the fourth factor. CONCLUSION: The cardiac rehabilitation self-efficacy questionnaire exhibited high validity, reliability, and desirable item commonalities. Therefore, it can be effectively employed in pertinent HAPA-based studies involving heart failure patients.