Reliability and Validity of EQ-5D in Malaysian Population
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This cross-sectional study, involving conveniently chosen respondents in the Klang Valley area, was designed to answer the question “Can EQ-5D be used as a QOL instrument in the National Health Morbidity Survey in Malaysia?”. The chosen versions (Malay, Tamil, and Mandarin) of the translated EQ-5D were tested for their reliability and validity. After a written consent was obtained from each respondent, a standardized questionnaire for self-completion was given. It took an average of 10–15 min to complete the questionnaire. Each respondent who returned the completed questionnaire was approached again with an identical copy of the questionnaire to assess the test-retest reliability after a 2-week interval. Reliability was assessed by analyzing the study instrument’s test-retest reliability, while a predictive validity was used to investigate the predictive strength of a composite index of the five factors of EQ-5D (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) on the overall perceived health (EQ VAS). An intraclass correlation (ICC), generated based on a single rate using the one way analysis of variance (ANOVA) model, was used to evaluate the test-retest reliability (Streiner and Norman 1995), while spearman rank correlation coefficient was used to quantify the predictive strength of a composite index of the five factors of EQ-5D on the overall perceived health (EQ VAS) (Elmes et al. 2006). It was surprising to note 1–2 folds increase in the reported cases for pain/discomfort and anxiety/depression, the same trend was observed across different versions of EQ-5D. The ICC values were found to be in the range of <0.01 to 0.92, while 0.61–0.86 were the range for the spearman rank correlation coefficient value. The findings in this study demonstrated the EQ-5D questionnaires translated by the EuroQOL Group had reasonable test-retest reliability and predictive validity results. With these results, it is hoped that these instruments will be incorporated into future National Health Morbidity Survey in Malaysia.
KeywordsEQ-5D Malaysia Reliability Quality of life
The authors thank the Director of General of the Ministry of Health Malaysia and also the Management of SEGi University College for the permission to publish this paper. We also thank Dr Lim Teck Onn, Director of Clinical Research Centre, Hospital Kuala Lumpur, Dr Jamaiyah Haniff and Dr Faridah Aryani for their valuable guidance during the study. In addition, we extend our appreciation to the logistic group members, Ms Geeta Appanah, Ms Gunavathy Selvaraj, Ms Rajaswari Karuppiah and their team members . We gratefully acknowledge the EuroQOL Group for the permission in using the Malay, Tamil and Mandarin version of the EQ-5D questionnaire. This project was funded by a grant (NMRR ID 08-1453-3048) from the Ministry of Health Malaysia.
- Chen, W. S. (2009). Questionnaire translation and psychometric properties evaluation. SEGi Review, 2(2), 62–71.Google Scholar
- Department of Statistics, Malaysia. (2002). Demographic trends in Malaysia with Special focus on women. In Department of Statistics Malaysia website. Retrieved from http://www.statistics.gov.my.
- Department of Statistics, Malaysia. (2009). Statistics Handbook Malaysia 2009. In Department of Statistics Malaysia website. Retrieved from http://www.statistics.gov.my.
- Department of Statistics, Malaysia. (2010). Population and housing census of Malaysia 2010 – preliminary count report. In Department of Statistics Malaysia website. Retrieved from http://www.statistics.gov.my/portal/download_Population/files/BPD/Laporan_Kiraan_Permulaan2010.pdf.
- Elmes, D. G., Kantowitz, B. H., & Roediger, H. L., III. (2006). Research methods in psychology. Belmont: Thomson Higher Education.Google Scholar
- Foy, P. (2001). P25: Intraclass correlation and variance components as population attributes and measures of sampling efficiency in PIRLS. In International Association for the Evaluation of Educational Achievement (IEA) website. Retrieved from http://www.iea.nl/fileadmin/user_upload/IRC2004/Foy.pdf.
- Guyatt, G. H., Van Zanten, S. J. O. V., Feeny, D. H., & Patrick, D. L. (1989). Measuring quality of life in clinical trials: a taxonomy and review. CMAJ, 140, 1441–1448.Google Scholar
- Institute for Public Health (IPH). (2008). The Third National Health and Morbidity Survey (NHMS III) 2006. Malaysia: Ministry of Health.Google Scholar
- Maurice, J., Staquet, R. H. D., & Peter, M. F. (1998). Quality of life assessment in clinical trials: methods and practice. New York: Oxford University Press.Google Scholar
- Nunnally, J. C., & Bernstien, I. H. (1994). Psychometric theory.3. New York: McGraw-Hill.Google Scholar
- Oppe, M., Rabin, R., & de Charro, F. (2007). EQ-5D user guide (version 1.0). In EuroQOL website. Retrieved from http://www.euroqol.org.
- Rabin, R., & de Charro, F. (2001). EQ-5D: a measure of health status from EuroQOL Group. The Finnish Medical Society Duodecim, Annals of Medicine, 33, 337–343.Google Scholar
- Streiner, D. L., & Norman, G. R. (1995). Health measurement scales: a practical guide to their development and use. New York: Oxford University Press.Google Scholar
- Uncommon Knowledge LLP. (2001–2010). Depression: understand it, treat it, beat it. In Uncommon Knowledge LLP website. Retrieved from http://www.clinical-depression.co.uk/dlp/depression-information/major-depression-facts.
- Varatharajan, S., Chen, W. S., Appannah, G., & Selvaraj, G. (2010). Psychometric properties of the Malay version of the EQ-5D in Malaysia. SEGi Review, 3(2), 46–52.Google Scholar
- Wee, H. L., Loke, W. C., Li, S. C., Fong, K. Y., Cheung, Y. B., Machin, D., et al. (2007). Cross-cultural adaptation and validation of singapore malay and tamil versions of the EQ-5D. Annals of the Academy of Medicine, Singapore, 36, 403–408.Google Scholar