The relationship between health-state utilities and the SF-12 in a generalpopulation

It would be a major advance if quality-of-life instruments could be transla ted into health-state utilities. The aim with this study was to investigate the relationship between the SF-12 and health-state utilities, based on re sponses to a postal questionnaire sent to a random sample of 8,000 inhabita nts, aged 20-84 years, in the general population. The questionnaire include d the SF-12, a rating-scale (RS) question, and a time-tradeoff (TTO) questi on; the response rate was 68%. Age, gender, and the 12 items of the SF-12 w ere used as explanatory variables in a linear regression analysis of the he alth-state utilities. The regression models explained about 50% of the Vari ance in the RS answers and about 25% of the variance in the TTO answers. Mo st of the SF-12 items were related to the health-state utilities in the exp ected ways, with especially strong results for the RS method, The results s uggest that the SF-12 can be converted to health-state utilities, but that further work is needed to reliably estimate the conversion function.