OP31 Is excess mortality in Glasgow an artefact of inadequate control for deprivation: a case-control study

Background: Scotland experiences higher mortality than the rest of Western Europe with Glasgow experiencing higher mortality than the rest of Scotland. This excess persists even when controlling for socio-economic status and levels of deprivation. Moreover, available measures of deprivation have accounted for less of the Glasgow excess over last 30 years. Many theories have been put forward to account for these differences and a recent review identified seventeen hypotheses. One hypothesis, investigated here, was an artefact of inadequate control for deprivation.<p></p> Methods: Previous analyses of Glasgow’s ‘excess’ within Scotland have been based on comparison with nationally derived deprivation groupings (e.g. quintiles, deciles). Glasgow’s unique deprivation profile in comparison to the rest of Scotland renders such approaches problematic. Our approach, therefore, is as follows: small area geographies (datazones) were ranked by the Scottish Index of Multiple Deprivation (SIMD) income domain. Using a case control design datazones in Glasgow (cases) were matched with the closest non Glasgow datazone ranked above and below (controls). Geocoded mortality and population data were available for all deaths by age and sex for 2000-2002. Age-standardised all-cause mortality rates were calculated for men and women between the ages of 0–64, and for all ages. Age-standardised mortality rates by sex were compared for cases and matched controls for each quintile of deprivation.<p></p> Results: Men in the 3 most deprived quintiles in Glasgow experienced higher levels of mortality compared to both the nearest non-Glasgow datazones and all non-Glasgow datazones within the quintile. Excess mortality was reduced for the 2 most affluent quintiles. The pattern was broadly similar for women, with the excess reduced for the 3 most affluent quintiles. The age-standardised mean mortality rate for men aged 0–64 in Glasgow in the most deprived quintile was 769 per 100,000. The corresponding rate for all non-Glasgow datazones was 582 per 100,000. The mortality rate for the control group was 688 per 100,000, suggesting a substantially smaller excess. Using this case-control approach, the excess is reduced by 57% in the most deprived quintile. In the second most deprived quintile it is reduced by 15%. The corresponding results for women are reductions of 57% (most deprived quintile) and 47% (second most deprived quintile).<p></p> Conclusion: Using national population and mortality data, the excess mortality in Glasgow in the most deprived area is halved by means of a closer control for deprivation. Explanations are still required for the remaining excess suggesting it is only partly artefactual.<p>