Health and Quality of Life Outcomes BioMed Central Research Open Access Do English and Chinese EQ-5D versions demonstrate measurement equivalence? an exploratory study Nan Luo1, Ling-Huo Chew2, Kok-Yong Fong3,4, Dow-Rhoon Koh3,4, SweeCheng Ng4, Kam-Hon Yoon3,4, Sheila Vasoo4, Shu-Chuen Li1 and Julian Thumboo*3,4 Address: 1Department of Pharmacy, National University of Singapore, Singapore, 2School of Health Sciences, Nanyang Polytechnic, Singapore, 3Department of Medicine, National University of Singapore, Singapore and 4Department of Medicine, National University Hospital, Singapore Email: Nan Luo - scip9152@; Ling-Huo Chew - CHEW_Ling_Huo@; Kok-Yong Fong - grifky@; DowRhoon Koh - phskohdr@; Swee-Cheng Ng - Swee_Cheng_Ng@; Kam-Hon Yoon - mdcykh@; Sheila Vasoo - sheilav@; Shu-Chuen Li -. | BioMed Central Health and Quality of Life Outcomes Research Open Access Do English and Chinese EQ-5D versions demonstrate measurement equivalence an exploratory study Nan Luo1 Ling-Huo Chew2 Kok-Yong Fong3 4 Dow-Rhoon Koh3 4 Swee- Cheng Ng4 Kam-Hon Yoon3 4 Sheila Vasoo4 Shu-Chuen Li1 and Julian Thumboo 3 4 Address Department of Pharmacy National University of Singapore Singapore 2School of Health Sciences Nanyang Polytechnic Singapore 3Department of Medicine National University of Singapore Singapore and 4Department of Medicine National University Hospital Singapore Email Nan Luo - scip9152@ Ling-Huo Chew - CHEW_Ling_Huo@ Kok-Yong Fong - grifky@ Dow- Rhoon Koh - phskohdr@ Swee-Cheng Ng - Swee_Cheng_Ng@ Kam-Hon Yoon - mdcykh@ Sheila Vasoo - sheilav@ Shu-Chuen Li - phalisc@ Julian Thumboo - grijt@ Corresponding author Published 17 April 2003 Received 11 March 2003 Accepted 17 April 2003 Health and Quality of Life Outcomes 2003 1 7 This article is available from http content 1 1 7 2003 Luo et al licensee BioMed Central Ltd. This is an Open Access article verbatim copying and redistribution of this article are permitted in all media for any purpose provided this notice is preserved along with the article s original URL. Abstract Background Although multiple language versions of health-related quality of life instruments are often used interchangeably in clinical research the measurement equivalence of these versions especially using alphabet vs pictogram-based languages has rarely been assessed. We therefore investigated the measurement equivalence of English and Chinese versions of the EQ-5D a widely used utility-based outcome instrument. Methods In a cross-sectional study either EQ-5D version was administered to consecutive outpatients with rheumatic diseases. Measurement equivalence of EQ-5D item responses and utility and visual analog scale EQ-VAS scores
