OBJECTIVE: The primary aim of this article was to evaluate measurement equivalence of the English and Chinese versions of the Short Form 36 version 2 (SF-36v2) and Short Form 6D (SF-6D). STUDY DESIGN AND SETTING: In this cross-sectional study, health-related quality of life (HRQoL) was measured from 4,973 ethnic Chinese subjects using the SF-36v2 questionnaire. Measurement equivalence of domain and utility scores for the English- and Chinese-language SF-36v2 and SF-6D were assessed by examining the score differences between the two languages using linear regression models, with and without adjustment for known determinants of HRQoL. Equivalence was achieved if the 90% confidence interval (CI) of the differences in scores, due to language, fell within a predefined equivalence margin. RESULTS: Compared with English-speaking Chinese, Chinese-speaking Chinese were significantly older (47.6 vs. 55.5 years). All SF-36v2 domains were equivalent after adjusting for known HRQoL. SF-6D utility/items had the 90% CI either fully or partially overlap their predefined equivalence margin. CONCLUSION: The English- and Chinese-language versions of the SF-36v2 and SF-6D demonstrated equivalence.
OBJECTIVE: The primary aim of this article was to evaluate measurement equivalence of the English and Chinese versions of the Short Form 36 version 2 (SF-36v2) and Short Form 6D (SF-6D). STUDY DESIGN AND SETTING: In this cross-sectional study, health-related quality of life (HRQoL) was measured from 4,973 ethnic Chinese subjects using the SF-36v2 questionnaire. Measurement equivalence of domain and utility scores for the English- and Chinese-language SF-36v2 and SF-6D were assessed by examining the score differences between the two languages using linear regression models, with and without adjustment for known determinants of HRQoL. Equivalence was achieved if the 90% confidence interval (CI) of the differences in scores, due to language, fell within a predefined equivalence margin. RESULTS: Compared with English-speaking Chinese, Chinese-speaking Chinese were significantly older (47.6 vs. 55.5 years). All SF-36v2 domains were equivalent after adjusting for known HRQoL. SF-6D utility/items had the 90% CI either fully or partially overlap their predefined equivalence margin. CONCLUSION: The English- and Chinese-language versions of the SF-36v2 and SF-6D demonstrated equivalence.