OBJECTIVE: To translate the DQoL-BCI into a Malaysian version and to assess its construct validity (factorial validity, convergent validity and discriminant validity), reliability (internal consistency) and floor and ceiling effects among the Malaysian diabetic population.

MATERIAL AND METHODS: A forward-backward translation, involving professional translators and experts with vast experience in translation of patient reported outcome measures, was conducted. A total of 202 patients with Type 2 diabetes mellitus (T2DM) who fulfilled the inclusion criteria were invited to complete the translated DQoL-BCI. Data were analysed using SPSS for exploratory factor analysis (EFA), convergent and discriminant validity, reliability and test-retest, and AMOS software for confirmatory factor analysis (CFA).

RESULTS: Findings from EFA indicated that the 4-factor structure of the Malaysian version of DQoL-BCI was optimal and explained 50.9% of the variance; CFA confirmed the 4-factor model fit. There was negative, moderate correlation between the scores of DQoL-BCI (Malaysian version) and EQ-5D-3L utility score (r = -0.329, p = 0.003). Patients with higher glycated haemoglobin levels (p = 0.008), diabetes macrovascular (p = 0.017) and microvascular (p = 0.013) complications reported poorer QoL. Cronbach's alpha coefficient and intraclass coefficient correlations (range) obtained were 0.703 and 0.86 (0.734-0.934), indicating good reliability and stability of the translated DQoL-BCI.