Relation of socioeconomic position to the case fatality, prognosis and treatment of myocardial infarction events; the FINMONICA MI Register Study

Objective-To examine socioeconomic differences in case fatality and prognos is of myocardial infarction (MI) events, and to estimate the contributions of incidence and case fatality to socioeconomic differences in coronary hea rt disease (CHD) mortality. Design-A population-based MI register study. Methods-The FINMONICA MI Register recorded all MI events among persons aged 35-64 years in three areas of Finland during 1983-1992. A record Linkage o f the MI Register data with the files of Statistics Finland was performed t o obtain information on socioeconomic indicators for each individual regist ered. First MI events (n=8427) were included in the analyses. Main results-The adjusted risk ratio of prehospital coronary death was 2.11 (95% CI 1.82, 2.46) among men and 1.68 (1.14, 2.48) among women with low i ncome compared with those with high income. Even among persons hospitalised alive the risk of death during the next 12 months was markedly higher in t he low income group than in the high income group. Case fatality explained 51% of the CHD mortality difference between the low and the high income gro ups among men and 38% among women, Incidence contributed 49% and 62%, respe ctively. Conclusions-Considerable socioeconomic differences were observed in the cas e fatality of first coronary events both before hospitalisation and among p atients hospitalised alive. Case fatality explained a half of the CHD morta lity difference between the low and the high income groups among men and mo re than a third among women.