Abstract
BACKGROUND: The Medication-Related Burden Quality of Life (MRB-QoL) Arabic version is a 31-item valid and reliable measure of medication burden on functioning and well-being. OBJECTIVE: To examine the factor structure of the MRB-QoL Arabic in a sample of adults living with long-term conditions (LTC). METHODS: Three hundred forty-three patients (≥ 18 years old) living with at least one LTC were recruited from 4 tertiary hospitals in the United Arab Emirates. Confirmatory factor analysis (CFA) was performed using Maximum likelihood estimation with bootstrap. Two models (first order and second order) were examined. Model fit indices, composite reliability (CR), and average variance extracted (AVE) were used to assess the model's goodness of fit, reliability, and convergent/discriminant validity, respectively. The model's fit was evaluated using absolute fit, comparative fit, and parsimony-adjusted indices. The RMSEA and SRMR ≤0.08, χ(2)/df < 5, and CFI, IFI, and TLI ≥ 0.90 were considered indicators of good model fit. PNFI and PCFI >0.5 were also considered as indicators of good fit. CR ≥ 0.7, AVE ≥ 0.5, and AVE greater than squared factors correlation were considered as evidence indicating reliability, convergent validity, and discriminant validity, respectively. RESULTS: The first-order model showed an excellent fit (χ2/df = 3.262, RMSEA = 0.08, SRMR = 0.05, CFI = 0.913, TLI = 0.914, IFI = 0.914, PNFI = 0.810, PCFI = 0.841) as did the second-order model (χ2/df = 2.845, RMSEA = 0.073, SRMR = 0.072, CFI = 0.934, TLI = 0.923, IFI = 0.915, PNFI = 0.820, PCFI = 0.851). All domains of the MRB-QoL met the convergent/discriminant validity and reliability criteria. CONCLUSIONS: The study supports the factor structure from previous research and confirms the MRB-QoL Arabic as a valid and reliable measure. This tool can be used to assess medicines burden from patient perspectives and facilitate person-centred care in medicines optimisation services across Arabic-speaking countries.