Validation of the EQ-5D in a general population sample in urban China

To evaluate the reliability and validity of the EQ-5D in a general population sample in urban China.

Thousand and eight hundred respondents in 18 communities of Hangzhou, China were recruited by multi-stage stratified random sampling. Respondents self-administered a questionnaire including the EQ-5D, the SF-36, and demographic questions. Test-retest reliability at 2-week intervals was evaluated using Kappa coefficient, the intraclass correlation coefficient. The standard error of measurement (SEM) was used to indicate the absolute measurement error. Construct validity was established using convergent, discriminant, and known groups analyses.

Complete data for all EQ-5D dimensions were available for 1,747 respondents (97%). Kappa values were from 0.35 to 1.0. The ICCs of test-retest reliability were 0.53 for the EQ-5D index score and 0.87 for the EQ VAS score. The SEM values were 0.13 (9.22% range) and 4.20 (4.20% range) for the EQ-5D index and EQ VAS scores, respectively. The Pearson's correlation coefficients between the EQ-5D and the SF-36 were stronger between comparable dimensions than those between less comparable dimensions, demonstrating convergent and discriminant evidence of construct validity. The Chinese EQ-5D distinguished well between known groups: respondents who reported poor general health and chronic diseases had worse HRQoL than those without. Older people, females, people widowed or divorced, and those with a lower socioeconomic status reported poorer HRQoL. Respondents reporting no problems on any EQ-5D dimension had better scores on the SF-36 summary scores than those reporting problems.

The Chinese version of the EQ-5D demonstrated acceptable construct validity and fair to moderate levels of test-retest reliability in an urban general population in China.