RELATIVE DEPRIVATION BETWEEN NEIGHBOURING WARDS IS PREDICTIVE OF CORONARY HEART DISEASE MORTALITY AFTER ADJUSTMENT FOR ABSOLUTE DEPRIVATION OF WARDS

Abstract

Backgrounds and aims: An association between income inequality and health has been widely reported, as has an association between levels of income inequality and poor health. Here we are interested in whether, at a small area level, health is affected by the relative deprivation of a ward compared to its neighbours. We aim to assess whether deprivation inequality at small area level in England is associated with coronary heart disease (CHD) mortality rates, and assess whether this provides evidence of an association between area-level and individual-level risk. Methods Mortality rates for all wards in England were calculated using all CHD deaths 2001 - 2006. Ward-level deprivation was measured using the Carstairs index. Deprivation inequality within local authorities was measured by the interquartile range of deprivation for wards within the local authority. Relative deprivation for wards was measured as the modulus of the difference between deprivation for the ward and average deprivation for all neighbouring wards. Results Deprivation inequality within local authorities was positively associated with CHD mortality rates after adjustment for absolute deprivation (p < 0.001 for all models). Relative deprivation for wards was positively associated with CHD mortality rates after adjustment for absolute deprivation (p < 0.001 for all models). Sub-group analyses showed that relative deprivation was independently associated with CHD mortality rates in both affluent and deprived wards. Conclusions Rich wards surrounded by poor areas have higher CHD mortality rates than rich wards surrounded by rich areas. Poor wards surrounded by rich areas have worse CHD mortality rates than poor wards surrounded by poor areas. Local deprivation inequality has a similar adverse impact on both rich and poor areas, supporting the hypothesis that income inequality of an area has an impact on individual-level health outcomes.