Neighborhood socioeconomic context, individual income and myocardial infarction

Abstract

Background: The incidence of myocardial infarction (MI) varies among socioeconomic groups, and geographic differences in incidence rates are observed within most urban regions. Whether spatial social differentiation gives rise to social contexts detrimental to health is still an open question. In this study, we evaluate 2 aspects of the neighborhood context as contributory factors in MI: level of economic resources and degree of socioeconomic homogeneity. We adopt a multilevel approach to analyze potential mechanisms, which involve individual social characteristics.

Methods: We analyzed data from the SHEEP study, a population-based case-control study of first events of acute MI in Stockholm County in 1992-1994. Data on socioeconomic characteristics in neighborhoods came from total population registers of income and social circumstances.

Results: The level of neighborhood socioeconomic resources had a contextual effect on the relative risk of MI after adjustment for individual social characteristics. The incidence rate ratio (IRR) in low-income, compared with high-income, neighborhoods was 1.88 for women and 1.52 for men. Although the degree of socioeconomic homogeneity in neighborhoods has less impact on MI, the IRR for men in homogenous low-income areas compared with men living in heterogeneous high-income areas was 2.65. For men, the combined exposure to low-personal disposable income and low-income level in the neighborhood seemed to have an additive effect but for women, a synergistic (supra-additive) effect was found.

Conclusion: The socioeconomic context of neighborhoods has an effect on cardiovascular outcomes.