Socioeconomic inequalities in cardiovascular mortality and the role of work: a register study of Finnish men.

Background: In Finland, socioeconomic inequalities in mortality have been well documented. However, the role of working conditions in the emergence of those inequalities has not been thoroughly examined.

Methods: Data came from the Longitudinal Census file, which included censuses since 1970 (every 5 years). The cohort consisted of men who were in the same occupation in 1975 and 1980, and who were between 25 and 64 years old in 1980. Farm work, mining and military occupations were excluded. Cardiovascular mortality of this cohort was followed up 1981-1994 (5.4 million person-years). Information on marital status, education and income was updated in 1985 and 1990. Working conditions were evaluated at occupational level (job exposure matrix). Poisson regression analyses were conducted to estimate the impact of independent variables on mortality. Inequalities were assessed in relation to occupational class and occupational category.

Results: According to the models, elimination of unfavourable working conditions would have reduced the number of all cardiovascular deaths by 8%, myocardial infarctions by 10%, and cerebrovascular deaths by 18%. The most influential job exposures appeared to be high workload, low control, noise, and shift work. Income had a strong effect on mortality.

Conclusions: Working conditions explained a relatively small portion of socioeconomic inequalities in mortality. Inequalities associated with occupational category and class were more attributable to varying levels of education and income.