Short Form 36 (SF-36) Health Survey Questionnaire: normative data for Wales

Background The Short Form 36 Health Survey Questionnaire (SF-36) is used to indicate the health status of particular populations, to help with service planning and to measure the impact of clinical and social interventions. Culture-specific data are required to calculate SF-36 norm-based scores. Currently, in the UK normative sources are nearly two decades old, Anglocentric and lack data on the older population. We draw on raw data from the Welsh Health Survey (2007) to provide population norms for the eight SF-36 dimensions for Wales and its regions. Methods We test the SF-36 dimensions for reliability and rating scaling assumptions and construct validity. We compare the Wales' norms to those reported in existing UK sources and examine the data between countries and by region. Results The scale is reliable and has content validity. The relationships found between the SF-36 domains and a range of variables known to be related to health also demonstrate construct validity. There are differences in population health norms between England and Wales and between the regions of Wales. Conclusions The results suggest that it is imperative that the accurate normative data provided in this paper is used in population studies in Wales to provide an indication of the health status of particular populations.