Feasibility, reliability, and validity of the EQ-5D-Y: results from a multinational study

Ravens-Sieberer U, Wille N, Badia X, et al. Feasibility, reliability, and validity of the EQ-5D-Y: results from a multinational study. QUALITY OF LIFE RESEARCH. 2010;19(6):887-897.To examine the feasibility, reliability, and validity of the newly developed EQ-5D-Y. The EQ-5D-Y was administered in population samples of children and adolescents in Germany, Italy, South Africa, Spain, and Sweden. Percentages of missing values and reported problems were calculated. Test-retest reliability was determined. Spearman's rank correlation coefficients with other generic measures of HRQOL were calculated. Known groups' validity was examined by comparing groups with a priori expected differences in HRQOL. Between 91 and 100% of the respondents provided valid scorings. Sweden had the lowest proportion of reported problems (1-24.9% across EQ-5D-Y dimensions), with the highest proportions in South Africa (2.8-47.3%) and Italy (4.3-39.0%). Percentages of agreement in test-retest reliability ranged between 69.8 and 99.7% in the EQ-5D-Y dimensions; Kappa coefficients were up to 0.67. Correlation coefficients with other measures of self-rated health indicated convergent validity (up to r = -0.56). Differences between groups classified according to presence of chronic conditions, self-rated overall health and psychological problems provided preliminary evidence of known groups' validity. Results provide preliminary evidence of the instrument's feasibility, reliability and validity. Further study is required in clinical samples and for possible future applications in economic analyses

Development of the EQ-5D-Y: a child-friendly version of the EQ-5D

Wille N, Badia X, Bonsel G, et al. Development of the EQ-5D-Y: a child-friendly version of the EQ-5D. QUALITY OF LIFE RESEARCH. 2010;19(6):875-886.To develop a self-report version of the EQ-5D for younger respondents, named the EQ-5D-Y (Youth); to test its comprehensibility for children and adolescents and to compare results obtained using the standard adult EQ-5D and the EQ-5D-Y. An international task force revised the content of EQ-5D and wording to ensure relevance and clarity for young respondents. Children's and adolescents' understanding of the EQ-5D-Y was tested in cognitive interviews after the instrument was translated into German, Italian, Spanish and Swedish. Differences between the EQ-5D and the EQ-5D-Y regarding frequencies of reported problems were investigated in Germany, Spain and South Africa. The content of the EQ-5D dimensions proved to be appropriate for the measurement of HRQOL in young respondents. The wording of the questionnaire had to be adapted which led to small changes in the meaning of some items and answer options. The adapted EQ-5D-Y was satisfactorily understood by children and adolescents in different countries. It was better accepted and proved more feasible than the EQ-5D. The administration of the EQ-5D and of the EQ-5D-Y causes differences in frequencies of reported problems. The newly developed EQ-5D-Y is a useful tool to measure HRQOL in young people in an age-appropriate manner