The reliability and validity of the Malay version of the 18-item audit of Diabetes Dependent Quality of Life (the Malay ADDQOL) questionnaire.

The objective of this study was to examine the reliability and validity of the Malay version of the 18-item Audit of Diabetes Dependent Quality of Life (the Malay ADDQOL). Patients with type 2 diabetes mellitus who fulfilled the inclusion criteria were systematically selected. The Malay ADDQOL linguistically validated from the 18-item English version ADDQOL was self-administered twice at a 1-week interval. Two hundred eighty-eight respondents were included in the study. Analysis involved checking the feasibility, floor and ceiling effects, internal consistency, test-retest reliability and factor analysis. Item means and standard deviations fulfilled the Likert scale assumptions. The Cronbach's alpha was 0.943 (lower bound of the 95% CI of 0.935) and the intraclass correlation coefficient was 0.81 (95% CI from 0.72 to 0.87). Exploratory one factor analysis showed factor loadings above 0.5 for all the 18 items. The Malay ADDQOL has acceptable linguistic validity. It is feasible, has excellent reliability, content, construct validity, and is recommended to be used among Malay-speaking diabetic patients.