The SF36 Version 2: critical analyses of population weights, scoring algorithms and population norms.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Hawthorne
Graeme
G
Department of Psychiatry, Royal Melbourne Hospital, The University of Melbourne, Level 1 North, Main Building, Grattan St, Parkville, VIC, 3052, Australia. graemeeh@unimelb.edu.au
Osborne
Richard H
RH
Taylor
Anne
A
Sansoni
Jan
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001294:Attitude to Health; D018864:Cultural Diversity; D003710:Demography; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation*; D012016:Reference Values; D012938:Social Perception; D013021:South Australia; D014481:United States