Census tract socioeconomic and physical environment and cardiovascular mortality in the Region of Madrid (Spain)

Background Features of the area might contribute to differences in cardiovascular mortality. The census tract distribution of ischaemic heart disease (IHD) and cerebrovascular disease mortality in the Region of Madrid and its association with deprivation and environmental variables were examined in this study. Methods Cross-sectional, ecological study covering 3906 census tracts (median of around 1000 inhabitants), using mortality data (population aged <75 years) for 1996-2003, as well as socioeconomic deprivation and other environmental indicators (subjective perceptions of pollution, background noise, lack of green spaces and delinquency) drawn from the 2001 census. Standardised mortality ratios were calculated. Smoothed census tract relative risks were calculated using the Besag-York-Mollie model. Relative risks (RRs) of dying and their 95% credibility intervals (95% CI) were calculated according to the indicators considered (with the fourth quartile, Q, being the most unfavourable situation). Maps were plotted depicting the distribution of the posterior probability of RR>1. Results Census tracts with excess mortality were mostly located in the city of Madrid. Mortality increased with deprivation: RRs of IHD and stroke mortality in Q4 with respect to Q1 were 1.42 (95% CI 1.31 to 1.54) and 1.66 (95% CI 1.45 to 1.88) for men, and 1.54 (95% CI 1.33 to 1.79) and 1.52 (95% CI 1.29 to 1.76) for women respectively. Associations with deprivation decreased only slightly when perceived lack of green spaces and delinquency were included in the model. In men, subjective perceptions of areas remained associated with cardiovascular mortality after adjustment for deprivation. Conclusion Deprivation and subjective perceptions of physical environmental characteristics are ecologically associated with cardiovascular disease mortality.