Psychometric properties of the Greek simplified medication adherence questionnaire among Iranian hemodialysis patients.

Patients suffering from chronic kidney failure ultimately need kidney replacement therapies, such as hemodialysis. Adherence to treatment in these patients can play a central role in improving health levels and feelings of well-being. The aim of this study was to determine the psychometric properties of the Persian version of the modified version of the Greek Simplified Medication Adherence Questionnaire in hemodialysis patients. In a methodological study carried out in 2024, a sample of 411 hemodialysis patients was selected using a convenience sampling method. The GR-SMAQ-HD utilized in the study was translated, and its psychometric properties were evaluated through assessments of construct validity, including exploratory and confirmatory factor analysis, convergent validity, and divergent validity. Furthermore, the study examined the internal consistency of the scale to ensure its reliability. The mean age of the participants was 59.37 (SD = 12.99) years. The results of the tetrachoric correlation matrix with Varimax with Kaiser Normalization rotation using the first random dataset (n = 205) extracted three factors accounting for 74.4% of the variance comprising 8 items. The results of CFA showed that the data fit the model. As for construct reliability, Cronbach's alpha, CR, AIC, and MaxR for all constructs were greater than 0.7, demonstrating good internal consistency and construct reliability. In the overall population, the mean score for treatment Adherence was 5.61 (SD = 1.95, 95% CI 5.42, 5.80). Invariance analysis shows that the model has strong measurement invariance between sex ($ΔCFI= - 0.001, ΔRMSEA= - 0.004$). The findings affirm the appropriateness of employing the Persian iteration of the GR-SMAQ-HD as a dependable and valid instrument for assessing adherence to treatment in hemodialysis patients. GR-SMAQ-HD is crucial for ensuring that patients follow their prescribed treatment regimens effectively.