How Comparable are Different Measures of Self-Rated Health? Evidence from Five European Countries
22 Pages Posted: 11 Aug 2009
Date Written: 2007
Self-rated health (SRH) is a common health measurement in international research. Yet different versions of this item are often applied. This study compares the US (United States) version (from excellent to poor) and the EU (European) version (from very good to very bad) of SRH, and examines differences in their associations with demographic and objective health variables. Data were drawn from the Survey of Health, Ageing and Retirement in Europe (SHARE), comprising information from 11,622 respondents aged 50 years and over in five countries. Respondents were presented with both the EU and US versions. Information was collected on basic demographics and health variables including chronic diseases, symptoms, functional limitations and depression. Firstly, the distribution of each version of the SRH item was assessed, and both relative and literal concordance was examined. Subsequently, multivariate regression analysis was used to assess differences in the associations of both items with demographic and health indicators. The US version has a more symmetric distribution and smaller variance than the EU version. Although the EU version discriminates better at the negative end, the US version shows better discrimination at the negative end of the scale. 69% of respondents provided literally concordant answers, while only about one third provided relatively concordant answers. Overall, however, less than 10% of respondents were discordant in either sense. Furthermore, the two versions were strongly correlated (polychoric correlation = 0.88), had similar associations with demographics and health indicators, and showed a similar pattern of variation across countries. Health levels based on different versions of the self-rated health item are not directly comparable and require rescaling of items. However, both versions represent parallel assessments of the same latent health variable. We did not find evidence that the EU version is preferable to the US version as standard measure of SRH in European countries.
Keywords: Self-rated health, world health, international comparisons, research design, Europe
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