Incapacity or unemployment? The utility of an administrative data source as an updatable indicator of population health

A lack of annually accessible morbidity information for small geographical areas in England and Wales means that health studies are often restricted to using decennial, self-reported census measures. Administrative data on health-related benefit claims, in the form of Incapacity Benefit (IB) data, are more regularly available and claimants are professionally diagnosed. This source may have the potential to be an annual indicator of population health. We examine IB as an indicator of population health at local government district and subdistrict levels by investigating distributions and relationships between IB and other health measures from the census and from mortality statistics. We found that relationships in 2001 between IB, census measures and mortality suggest that using IB as an indicator of population health will give very similar results, especially with those reporting themselves in the 2001 Census as ‘permanently sick or disabled’ and in the more urban areas. Although IB should be an objective measure as it is professionally diagnosed, we recognise that IB may hide unemployment and have inferred an estimate using census data on economic activity by exploring the relationship between IB and those reporting themselves permanently sick or disabled. This estimate suggests that previous assertions about the relationship between IB and unemployment may have been overzealous. On balance, IB is currently a useful indicator of relative health for small areas.