Reliability and validity of the Turkish translation of the beliefs about medicines questionnaire (BMQ-T) in patients with Behçet's disease

Abstract

Objectives: The aim of this study was to evaluate the reliability and validity of the Turkish translation of the Beliefs about Medicines Questionnaire (BMQ-T, ©Prof. Rob Horne) for patients with Behçet's disease.

Methods: This methodological study enrolled a sample of 125 patients. The scale was adapted to Turkish through a process including translation, comparison with versions in other languages, back translation, and pretesting. Construct validity was evaluated by factor analysis. Medication adherence evaluated as poor, moderate and good according to the Morisky Medication Adherence Scale (MMAS). BMQ-T scores compared along medication adherence status groups.

Results: In our study, as in the original scale, the factor analysis confirmed that the BMQ-T had a four-factor structure explaining 54.73% of the total variance. The BMQ-T had acceptable internal consistency (Cronbach's alpha coefficient: Specific Necessity=.812; Specific Concerns=.672; General Harm=.677; General Overuse=.656), adequate test-retest reliability (intraclass correlation coefficients: Specific Necessity=.715; Specific Concerns=.680; General Harm=.678; General Overuse=.327). Specific Necessity and Specific Concerns scores were significantly different between medication adherence status groups.

Conclusions: The psychometric properties of the BMQ-T were consistent with those reported in the original study. The BMQ-T was found to be a valid and reliable tool for evaluating beliefs about medicines in patients with Behçet's disease.