Disentangling the relative importance of different socioeconomic resources for myocardial infarction incidence and survival: a longitudinal study of over 300,000 Finnish adults.

Background: Lower socioeconomic position (SEP) is associated with an increased risk of myocardial infarction (MI) incidence and mortality, but the relative importance of different socioeconomic resources at different stages of the disease remains unclear.

Methods: A nationally representative register-based sample of 40- to 60-year-old Finnish men and women in 1995 (n= 302 885) were followed up for MI incidence and mortality in 1996-2007. We compared the effects of education, occupation, income and wealth on first MI incidence, first-day and long-term fatality. Cox's proportional hazards regression and logistic regression models were estimated adjusting for SEP covariates simultaneously to assess independent effects.

Results: Fully adjusted models showed greatest relative inequalities of MI incidence by wealth in both sexes, with an increased risk also associated with manual occupations. Education was a significant predictor of incidence in men. Low income was associated with a greater risk of death on the day of MI incidence [odds ratio (OR) = 1.40 in men and 1.95 in women when comparing lowest and highest income quintiles], and in men, with long-term fatality [hazard ratio (HR) = 1.74]. Wealth contributed to inequalities in first-day fatality in men and in long-term fatality in both sexes.

Conclusion: The results show that different socioeconomic resources have diverse effects on the disease process and add new evidence on the significant association of wealth with heart disease onset and fatality. Targeting those with the least resources could improve survival in MI patients and help reduce social inequalities in coronary heart disease mortality.