Are English and Chinese Versions of the Audit of Diabetes-Dependent Quality of Life Equivalent? An Exploratory Study Based on the Universalist Approach

Objective: To translate and culturally adapt the UK English Audit of Diabetes-Dependent Quality of Life (ADDQOL) into Chinese for Singapore. Methods: Translation was integrated into investigation of conceptual, item, semantic, and operation equivalence. Conceptual equivalence, item equivalence, and operation equivalence were assessed by literature review, expert judgment, and cognitive debriefing. Semantic equivalence was studied by using an optimized procedure including forward and backward translation, clinician review, and cognitive debriefings. Cognitive debriefings were done with five Chinesespeaking diabetic patients at polyclinics. Reliability, responsiveness, and construct validity tests were used to evaluate measurement equivalence. English- and Chinese-speaking diabetic patients by convenient sampling at a Diabetes Society of Singapore’s public event were recruited for the measurement equivalence study. Mann-Whitney U tests, chi-square tests, and descriptive analyses were used for group comparisons and Spearman’s correlation coefficients for construct validity tests. Results: Forty-two English-speaking and 26 Chinesespeaking diabetic patients (45.5% females) with a mean age of 54.2 10.07 years were recruited. Chinese-speaking respondents were more likely than the English-speaking group to be unemployed, less educated, and with poorer family functioning (P 0.05). Conceptual equivalence, item equivalence, operation equivalence, and semantic equivalence were all demonstrated. Cronbach’s alpha for internal consistency and intraclass correlation coefficient for test-retest reliability were 0.94 and 0.65, respectively. Distributions of responses were found to be similar except for some difference that can be justified by different demographic background. Convergent validity was suggested by weak to moderate correlations between “Present QOL” on the ADDQOL and EuroQol five-dimensional questionnaire (r 0.268; P 0.185) and six-dimensional health state short form (derived from short form 36 health survey) scores (r 0.351; P 0.078); divergent validity was shown by a weak correlation between ADDQOL average weighted impact (AWI) and ADDQOL “Present QOL” scores (r 0.027, P 0.896), a moderate correlation between ADDQOL AWI and six-dimensional health state short form (derived from short form 36 health survey) mental scores (r 0.247; P 0.224), and a positive correlation between ADDQOL AWI and family functioning scores (r 0.288; P 0.182). Conclusions: The ADDQOL has been translated and culturally adapted successfully into a Chinese version for Singapore. Our study provides justification for further research with large sample sizes among the Chinese-speaking population in Singapore.