The SF36 Version 2: critical analyses of population weights, scoring algorithms and population norms
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The SF36 Version 2 (SF36V2) is a revision of the SF36 Version 1, and is a widely used health status measure. It is important that guidelines for interpreting scores are available.
A population sample of Australians (n = 3015) weighted to achieve representativeness was administered the SF36V2. Comparisons between published US weights and sample derived weights were made, and Australian population norms computed and presented.
Significant differences were observed on 7/8 scales and on the mental health summary scale. Possible causes of these findings may include different sampling and data collection procedures, demographic characteristics, differences in data collection time (1998 vs. 2004), differences in health status or differences in cultural perception of the meaning of health. Australian population norms by age cohort, gender and health status are reported by T-score as recommended by the instrument developers. Additionally, the proportions of cases within T-score deciles are presented and show there are important data distribution issues.
The procedures reported here may be used by other researchers where local effects are suspected. The population norms presented may be of interest. There are statistical artefacts associated with T-scores that have implications for how SF36V2 data are analysed and interpreted.
KeywordsSF-36 Population norms Emic effects Health status Cultural differences Scoring weights
We would like to thank Mr Nick Marosszeky for his valuable comments on the manuscript.
This project was supported by a grant from the Community Care Branch, Australian Commonwealth Department of Health and Ageing, as part of the National Continence Management Strategy. The collection of data was carried out by the Population Research and Outcome Studies Unit, South Australian Department of Health. Dr Richard Osborne is supported in part by the Baker Trust, Buckland Foundation, the Arthritis Foundation of Australia, and by the National Health and Medical Research Council Career Development Award Population Health Fellowship.
Finally, our thanks go to those South Australians who gave their time to complete the questionnaire.
- 1.Ware, J. E., Snow, K. K., Kosinski, M., & Gandek, B. (1993). SF-36 health survey: Manual and interpretation guide. Boston: The Health Institute, New England Medical Centre.Google Scholar
- 3.McCallum, J. (1994). The new ‘SF-36–health status measure: Australian validity tests. Canberra: National Centre for Epidemiology and Population Health. 2.Google Scholar
- 7.Ware, J. E., Kosinski, M. A., & Dewey J. E. (2000). How to score version 2 of the SF-36 health survey. Lincoln: Quality Metric Inc.Google Scholar
- 9.Bullinger, M., Alonso, J., Apolone, G., Leplège, A., Sullivan, M., Wood Dauphinee, S., Gandek, B., Wagner, A., Aaronson, N., Bech, P., Fukuhara, S., Kaasa, S., & Ware, J.E. Jr. (1998). Translating health status questionnaires and evaluating their quality: The IQOLA Project approach. International Quality of Life Assessment. Journal of Clinical Epidemiology, 51, 913–23.CrossRefPubMedGoogle Scholar
- 17.Keller, S. D., Ware, J. E. Jr., Gandek, B., Aaronson, N. K., Alonso, J., Apolone, G., Bjorner, J. B., Brazier, J., Bullinger, M., Fukuhara, S., Kaasa, S., Leplège, A., Sanson Fisher, R. W., Sullivan, M., & Wood Dauphinee, S. (1998). Testing the equivalence of translations of widely used response choice labels: Results from the IQOLA Project. International Quality of Life Assessment. Journal of Clinical Epidemiology, 51, 933–44.CrossRefPubMedGoogle Scholar
- 21.McCall, W. A. (1922). How to measure in education. New York: Macmillan.Google Scholar
- 25.Sansoni, J., & Costi, J. (2001). SF-36: Version 1 or Version 2: The need for Australian normative data. Proceedings of Health Outcomes 2001: The Odyssey Advances Conference. Canberra: Australian Health Outcomes Collaboration.Google Scholar
- 26.ABS (1997). National Health Survey: SF-36 Population Norms, Australia. Canberra: Australia Bureau of Statistics.Google Scholar
- 27.Harrison Health Research (2004). Findings from Autumn 2004 Health Omnibus Survey. Adelaide, Harrison Health Research.Google Scholar
- 28.Wilson, D., Wakefield, M., & Taylor, A. (1992). The South Australian Health Omnibus Survey. Health Promotion Journal of Australia, 2, 47–9.Google Scholar
- 29.Ware, J., Kosinski, M., & Keller, S. (1994). SF-36 physical and mental health summary scales: A user’s manual Boston: The Health Institute, New England Medical Centre.Google Scholar
- 30.Feeny, D., Furlong, W., & Torrance, G. (1996). Health Utilities Index Mark 2 and Mark 3 (HUI2/3) 15-item questionnaire for self-administered, self-assessed usual health status. Hamilton: Centre for Health Economics and Policy Analysis, McMaster University.Google Scholar
- 31.ABS (2005). 3235.4.55.001–Population by age and sex, South Australia Canberra: Australian Bureau of Statistics.Google Scholar
- 32.ABS (2003). 2001.0–Census of population and housing: Basic community profiles, 2001 Canberra.Google Scholar
- 33.SPSS (2004). SPSS for Windows, Version 13.0 Chicago: SPSS Inc.Google Scholar
- 40.Ware, J., Gandek, B., & Keller, S. (1996). Evaluating instruments used cross-nationally: Methods from the IQOLA project. In B. Spilker (Ed.), Quality of Life and Pharmacoeconomics (pp. 681–92). Philadelphia: Lippincott-Raven Publishers.Google Scholar
- 42.Szabo, S., Orley, J., Saxena, S., & The WHOQOL Group. (1997). An approach to response scale development for cross-cultural questionnaires. European Psychologist, 2, 270–76.Google Scholar
- 45.Ware, J. E. Jr., Gandek, B., Kosinski, M., Aaronson, N. K., Apolone, G., Brazier, J., Bullinger, M., Kaasa, S., Leplege, A., Prieto, L., Sullivan, M., & Thunedborg K. (1998). The equivalence of SF-36 summary health scores estimated using standard and country-specific algorithms in 10 countries: Results from the IQOLA Project. International Quality of Life Assessment. Journal of Clinical Epidemiology, 51, 1167–170.CrossRefPubMedGoogle Scholar
- 46.Angst, F., Aeschlimann, A., & Stucki, G. (2001). Smallest detectable and minimal clinically important differences of rehabilitation intervention with their implications for required sample sizes using WOMAC and SF-36 quality of life measurement instruments in patients with osteoarthritis of the lower extremities. Arthritis Care and Research, 45, 384–91.CrossRefPubMedGoogle Scholar
- 47.Kosinski, M., Zhao, S. Z., Dedhiya, S., Osterhaus, J. T., & Ware, J.,E. Jr. (2000). Determining minimally important changes in generic and disease-specific health-related quality of life questionnaires in clinical trials of rheumatoid arthritis. Arthritis and Rheumatism 43, 1478–487.CrossRefPubMedGoogle Scholar
- 52.Bessette, L., Sangha, O., Kuntz, K. M., Keller, R. B., Lew, R. A., Fossel, A. H., & Katz, J. N. (1998). Comparative responsiveness of generic versus disease-specific and weighted versus unweighted health status measures in carpal tunnel syndrome. Medical Care, 36, 491–02.CrossRefPubMedGoogle Scholar
- 55.ABS (2002). Year Book Australia. Canberra: Australian Bureau of Statistics.Google Scholar