Background: Evaluating knowledge in patients with coronary artery disease requires a specific measure. The aim of the present study was to translate and evaluate the CADE-Q in patients with coronary artery disease in Iran.
Methods: Forward-backward procedure was applied to translate the questionnaire from English into Persian. Then a cross-sectional study was conducted to evaluate psychometric properties of the questionnaire. A sample of patients with coronary artery disease attending to cardiac departments of teaching hospitals affiliated to medical universities in Tehran, Iran completed the 19-item CADE-Q from April to December 2017. Structural validity of CADE-Q was assessed using both exploratory and confirmatory factor analyses. Reliability was examined using Cronbach's alpha coefficient. Stability was evaluated by estimation intraclass correlation coefficient.
Results: In all 500 patients participated in the study. The mean age of patients was 53.63. (SD = 14.36) years, and 57% were male. The results obtained from the exploratory factor analysis showed a four factor solution (lifestyle habits and exercise, risk factors, diagnosis and treatment, signals & symptoms and medicine) that jointly explained 48.9% of the total variance observed. However, the second-order confirmatory factor analysis supported the three-factor solution while convergent and divergent validity were not confirmed. Finally, the Cronbach's alpha coefficient of 0.84 ranging from 0.50 to 0.82 was obtained for the scale and its subscales. In addition, the ICC value of 0.88 showed satisfactory stability for the questionnaire.
Conclusion: The Coronary Artery Disease Education Questionnaire was found to be a multidimensional instrument. The results confirmed the factor structure of the questionnaire with a second-order analysis. Since the convergent and divergent validity of the scale were not confirmed, further assessment is essential to establish fitness of the questionnaire in Iran.
Keywords: Coronary artery disease; Knowledge; Psychometric analysis; Reliability; The CADE-Q; Validity.