Translation, cultural adaptation, and validation of the Arabic version of the Medication Adherence Universal Questionnaire among Omani patients with type 2 diabetes mellitus

Abstract

This study aimed to translate, culturally adapt, and validate an Arabic version of the Medication Adherence Universal Questionnaire (MAUQ-ar-OM) for Omani adults with type 2 diabetes mellitus (T2DM), and to assess its association with glycated hemoglobin (HbA1c). A cross-sectional psychometric validation was conducted at a tertiary-care hospital in Oman from October 2024 to January 2025, enrolling 300 participants. The MAUQ was translated and culturally adapted using forward-backward translation, expert panel review (n = 4), and cognitive interview testing and then administered by a trained clinical pharmacist using a standardized script. Confirmatory factor analysis (CFA) compared second order and bifactor models using CFI, TLI, RMSEA (90% CI) and SRMR. Convergent validity with HbA1c was assessed using Spearman's correlation (rho). The bifactor model showed superior fit indices (CFI = 0.904; TLI = 0.868; RMSEA = 0.055; SRMR = 0.057) compared with the second-order model (CFI = 0.849; TLI=0.819). Cronbach's alpha coefficients for total scores, positive attitude towards healthcare and medication (PAM), lack of discipline, aversion towards medication and active coping with health problems subscales were 0.69, 0.71, 0.67, 0.59 and 0.42, respectively. The PAM subscale showed small inverse correlation with HbA1c (rho = -0.157; 95% CI: - 0.269 to - 0.041; p < 0.01), whereas other subscales and the total score showed no significant correlation. The MAUQ-ar-OM demonstrates construct validity for assessing medication adherence beliefs and behaviors among Arabic-speaking Omani adults with T2DM, with the bifactor structure supporting domain-level interpretation and the total score used descriptively. Further research is warranted to confirm reliability and generalizability across other Arabic-speaking populations, conditions and administration modes.