Psychometric evaluation of Persian version of cardiac depression scale in Iranian patients with acute myocardial infarction

Background and Objective: The feeling of impending death causes mood disorders such as depression in cardiac patients. Depression occurs three times more often in patients after MI than the general population. The Cardiac Depression Scale (CDS) is the only scale designed for screening of depression among psychosomatic disorders in cardiac patients with the sensitivity range of mild to severe. Therefore, the present study aims to determine the psychometric evaluation of CDS in patients with acute MI. Materials and Methods: This methodological study was conducted in 2015. A total of 407 AMI patients were randomly collected from coronary care unit (CCU) of two Hospitals in Sari and Amol, Iran according to inclusion criteria (such as ST segment changes in Electrocardiogram). The minimum sample size for conducting factor analysis is 5–10 times more than the number of the items of intended instrument. A demographic and the CDS questionnaire were used for data collection.The face, content and construct (factorial, convergent, and discriminant) validities of the CDS were evaluated using a sample of 407 AMI patients. Confirmatory factor analysis was conducted using the ratio chi-square by degrees of freedom (χ2/df), the Goodness-of-fit index (GFI), Comparative Fit Index (CFI), Incremental Fit Index (IFI), Normed Fit Index (NFI), and Root Mean Square Error of Approximation (RMSEA). Convergent and discriminant validity was assessed using Average Variance Extracted (AVE), maximum shared squared variance (MSV), and average shared square variance (ASV). Internal consistency was assessed using the Cronbach’s alpha coefficient and the Composite Reliability (CR) was estimated. All the above statistical procedure was performed by SPSS Findings: A total of 407 acute myocardial infarction patients participated in the study, with a mean age of 63.72 (SD=16.37) years. Of these participants, 55 % were male. Based on PCA and consideration of conceptual meaning, a two-factor solution was selected, explaining 56.792% of the total variance. Goodness-of-fit indices (2(103) =1298.075, P<0.05, 2/df = 12.603, GFI=0.714, CFI=0.754, NFI=0.739, IFI=0.755, RFI=0.696, TLI=0.713, Standardized RMR=0.090, RMSEA=0.169 in the final CDS structure demonstrated the adequacy of the twodomain structure of the CDS. Convergent and discriminant validity of construct fulfilled. The cronbach’s alpha and construct reliability were greater than 0.70. Conclusions: The result of current study about CDS demonstrated a sufficient validity and reliability among AMI patients. According to the importance of mental health in prevention of the occurrence of problems related to the AMI patients, the presence of the above mentioned tools could be useful in the precise measurement of depression.

Psychometric, Depression, Acute Myocardial Infarction, Patients