Validity of EQ-5D in general population of Taiwan: results of the 2009 National Health Interview and Drug Abuse Survey of Taiwan

Abstract

Purpose: The aim of this study was to examine the validity of the EuroQOL five dimensions questionnaire (EQ-5D) using a nationally representative data from the National Health Interview Survey (NHIS) through comparison with short-form 36 (SF-36).

Methods: Data for this study came from the 2009 NHIS in Taiwan. The study sample was the 4007 participants aged 20-64 years who completed the survey. We used SUDAAN 10.0 (SAS-Callable) to carry out weighed estimation and statistical inference. The EQ index was estimated using norm values from a Taiwanese study as well as from Japan and the United Kingdom (UK). The SF-36 score was standardized using American norm values.

Results: In terms of concurrent validity, the EQ-5D met the five hypotheses. The results did not fulfill hypothesis that women would have lower visual analogue scale (EQ-VAS) scores. In terms of discriminant validity, the EQ-5D fulfilled two hypotheses. Our results approached but did not fulfill hypothesis that there would be a weak association between the physical and psychological dimensions of the EQ-5D and the mental component summary score of the SF-36. Results were comparable regardless of whether the Japanese or UK norm value sets were used.

Conclusions: We were able to fulfill many, not all of our validity hypotheses regardless of whether the established Japanese or UK norm value sets or the Taiwanese norm values were used. The EQ-5D is an effective and simple instrument for assessing health-related quality of life of general population in Taiwan.

Keywords: EQ-5D; NHIS; SF-36; Taiwan; Validity.