Assessing the Psychometric Properties of the Persian Version of the Adaptation to Chronic Illness Scale for Patients With Cardiovascular Diseases

Objective Patients with cardiovascular diseases (CVDs) often face numerous psychosocial challenges and emotional fluctuations due to their chronic conditions. Their ability to adapt to the disease and manage the emotional, psychological, and social challenges is crucial for these individuals. This study aimed to assess the psychometric characteristics of the Persian version of the adaptation to chronic illness scale (ACIS) for patients with CVDs in Iran. Materials & Methods This is a cross-sectional and psychometrics study. The forward-backward translation method was first used to translate the ACIS. To assess its face validity, it was administered to 10 CVD patients and reviewed by five experts in counseling and psychology. The content validity index (CVI) and the content validity ratio (CVR) were calculated to assess content validity. Concurrent validity was evaluated by measuring the correlation between the scores of the Persian ACIS and the psychosocial adjustment to illness scale (PAIS). Internal consistency was assessed using Cronbach’s α coefficient, and test re-test reliability was measured using the intraclass correlation coefficient (ICC). Confirmatory factor analysis (CFA) was performed in LISREL software to validate the structure of the questionnaire. Results The CVR was obtained as 0.99, the item-CVI ranged from 0.8 to 1, and the calculated kappa coefficient ranged from 0.76 to 1. There was a strong correlation between the total scores of the ACIS and PAIS (r=-0.757, P<0.05). The Cronbach’s α coefficient for the overall scale was 0.84. Furthermore, the ICC was 0.96. The values of fit indices for the initial model were RMSEA=0.104, df=3.04, GFI=0.75, AGFI=0.70, and NFI=0.72. After removing item 10 (in the physical subscale) due to its lack of significance, and calculating the covariation of errors for paired items (22 & 23, 13 & 15, 17 & 19, 12 & 20, and 6 & 25), the values of fit indices improved as RMSEA=0.077, df=2.23, GFI=0.90, AGFI=0.91, and NFI=0.90, reaching acceptable construct validity. Conclusion The Persian ACIS has acceptable face and content validity, concurrent validity, internal consistency, and test re-test reliability. The results also confirmed its three-factor structure with 24 items for CVDs. Thus, it can be utilized in research and clinical settings in Iran for patients with CVDs.