Socioeconomic status and risk of acute myocardial infarction. Population-based case-control study

Socioeconomic status is associated with cardiovascular mortality. The aims of this study were to investigate the association between socioeconomic status and its various indicators and the risk of acute myocardial infarction (AMI), and to determine whether any association found is independent of the presence of cardiovascular risk factors (CVRFs).

Study cases were matched with controls by age, sex and year of recruitment. Cases were recruited from a hospital register and controls from cross-sectional studies of the general population. The socioeconomic status was determined from educational level and social class, as indicated by occupation. Self-reported data were collected on the presence of CVRFs.

The study included 1369 cases and controls. Both educational level and social class influenced AMI risk. Among non-manual workers, there was an inverse linear relationship between educational level and AMI risk independent of CVRFs: compared with university educated individuals, the odds ratio (OR) for an AMI among those with a high school education was 1.63 (95% confidence interval [CI], 1.16-2.3), and among those with an elementary school education, 3.88 (95% CI, 2.79-5.39). No association between educational level and AMI risk was observed in manual workers. However, the AMI risk was higher in manual workers than non-manual university educated workers: in those with an elementary school education, the increased risk (OR=2.09; 95% CI, 1.59-2.75) was independent of CVRFs.

An association was found between socioeconomic status and AMI risk. The AMI risk was greatest in individuals with only an elementary school education, irrespective of CVRFs and social class, as indicated by occupation.