Inter-mediating risk factors in the relation between socioeconomic status and 25-year mortality (the Zutphen Study).

In the Zutphen Study data were collected on occupation, smoking habits, blood pressure, serum cholesterol, height and weight of 856 men who were 40-59 years old in 1960. Between 1960 and 1985 detailed information was collected on mortality. The effect of socioeconomic status as indicated by occupation on 25-year mortality was studied in relation to cigarette smoking, systolic blood pressure, serum cholesterol and Body Mass Index. It was found that socioeconomic status was an important determinant of mortality only in the men who were 40-49 years old in 1960. The risk of all-cause mortality among small business owners and manual workers was more than twice as high as that of men in the highest social class. After adjustment for the influence of cigarette smoking and systolic blood pressure these relationships remained. It can be concluded that socioeconomic status was an independent risk factor for long-term all-cause mortality, in men aged 40-49.