Psychometric Measurements of the Adherence to Refills and Medication Scales Among Patients With HIV/AIDS in Indonesia

Objective: This study aimed to conduct a psychometric evaluation of the Adherence to Refills and Medications Scale (ARMS) among patients with HIV/AIDS in Indonesia. Methods: Psychometric analysis was conducted at 2 hospitals and 7 public health centers at the voluntary counseling and testing clinic. Content validity was measured by assessing the relevance and clarity of each ARMS item. Construct validity was also assessed. Reliability was evaluated using internal consistency and test-retest reliability. Results: This study involved 11 experts in the assessment of the content validity and 240 participants in the estimation of the construct validity. All ARMS items were generally considered easy to understand and relevant, with scale-level content validity index based on the average method (S-CVI/Ave) of 0.9 (>0.78) and item-level content validity index (I-CVI) in the range from 0.5 to 1 for the relevance level and S-CVI/Ave of 0.95 (>0.78) and I-CVI in the range from 0.8 to 1 for the clarity level. Two items (numbers 2 and 3) were revised based on experts’ suggestions to enhance comprehension. Confirmatory factor analysis supported 2 subscales: adherence to taking medications and adherence to refilling prescriptions. Good reliability was supported by internal consistency (Cronbach's α 0.793) and test-retest reliability (intraclass correlation coefficient 0.722) for the overall adherence score. Conclusions: The Indonesian version of ARMS is a valid and reliable medication adherence scale when used in Indonesian patients with HIV/AIDS. © 2024 International Society for Health Economics and Outcomes Research