Rethinking and rescoring the SF-12.

OBJECTIVES

To derive and assess the validity of an Australian version of the SF-12 quality-of-life questionnaire.

METHODS

Using regression methods and structural equation modelling to obtain item weights, an Australian version of the SF-12 was derived from Australian population survey data and compared to the existing United States (US) SF-12 variable set.

RESULTS

The Australian version of the SF-12 explained 94% of the variation for physical components summary (PCS) and the mental components summary (MCS) of the SF-36 questionnaire. There was high level of agreement on the MCS and PCS summary scores between both versions of the SF-12 and the SF-36.

CONCLUSIONS

Although it is possible to derive a valid Australian version of the SF-12 it is concluded the US version of the SF-12 be used for reasons of international comparability, but using item weights derived from structural equation modelling.