Differences in cardiovascular disease mortality between local authorities in England: an ecological analysis

Abstract

BackgroundLarge inequalities in age-standardised mortality rates of cardiovascular disease (CVD) exist at the local authority level within England, with particular areas consistently having the highest rates. Higher deprivation is associated with higher CVD mortality, but we know little about how the demographics and environments of local areas contribute to variations in mortality rates. The aim of this study was to explore the extent to which demographic, health, and environmental factors explain differences in all ages and premature CVD mortality between local authorities in England. MethodsAll data were sourced for each local authority in England. Outcome variables were age-standardised CVD mortality for all ages and those under 75 years in 2012–14. Data obtained were prevalence of ethnic and socioeconomic groups from the UK 2011 census; Public Health England data on index of multiple deprivation (IMD) score; prevalence of smoking, physical activity, obesity and overweightness; and Ordnance Survey environmental data on percentage of food shops, eating out shops, green or blue space, sporting facilities, and health facilities. We used the Akaike Information Criterion to assess which types of variables provided the best statistical model to explain variation in CVD mortality between local authorities. FindingsInclusion of health, demographic, environment, and IMD variables provided the best fit for explaining variation in CVD mortality at all ages (adjusted r2=0·60). Indian and Pakistani ethnicity and the IMD score in local authorities remained significantly associated with the outcome, with corresponding p values all less than 0·01. CVD mortality was 44 per 100 000 population greater in areas with the highest proportions of Indian and Pakistani ethnicities and 110 per 100 000 greater in the most deprived local authorities than in the least deprived areas. For CVD mortality below age 75, exclusion of environmental data improved the fit of the model (adjusted r2=0·82). Overweight prevalence (p=0·0481), Indian (p=0·0111), Pakistani (p=0·0003), and Bangladeshi (p=0·003) ethnicity, and the IMD score (p<0·0001) all remained significantly associated with premature CVD mortality when the best fitting model was used. Premature mortality was 13 per 100 000 and 18–25 per 100 000 greater in local authorities where the proportion of overweight people and Asian ethnicities was highest. Premature mortality in the most deprived local authorities was 68 per 100 000 greater than in the least deprived authorities. InterpretationThese findings are valuable for understanding which factors might be most useful for local authorities to target to reduce CVD mortality. This study combined a large amount of existing data; however, it was conducted at an ecological level, so analyses using individual-level mortality outcomes are also needed. FundingThe authors' posts are funded by the British Heart Foundation.