Workplace socioeconomic characteristics and coronary heart disease: a nationwide follow-up study.

Objectives: Important gaps in previous research include a lack of studies on the association between socioeconomic characteristics of the workplace and coronary heart disease (CHD).We aimed to examine two contextual factors in association with individuals' risk of CHD: the mean educational level of all employees at each individual's workplace (education) and the neighbourhood socioeconomic characteristics of each individual's workplace (neighbourhood SES).

Design: Nationwide follow-up/cohort study.

Setting: Nationwide data from Sweden.

Participants: All individuals born in Sweden from 1943 to 1957 were included (n=1 547 818). We excluded individuals with a CHD diagnosis prior to 2008 (n=67 619), individuals without workplace information (n=576 663), individuals lacking residential address (n=4139) and individuals who had unknown parents (n=7076). A total of 892 321 individuals were thus included in the study (426 440 men and 465 881 women).

Primary And Secondary Outcome Measures: The outcome variable was incident CHD during follow-up between 2008 and 2012. The association between education and neighbourhood SES and the outcome was explored using multilevel and cross-classified logistic regression models to determine ORs and 95% CIs, with individuals nested within workplaces and neighbourhoods. All models were conducted in both men and women and were adjusted for age, income, marital status, educational attainment and neighbourhood SES.

Results: Low (vs high) education was significantly associated with increased CHD incidence for both men (OR 1.29, 95% CI 1.23 to 1.34) and women (OR 1.38, 95% CI 1.29 to 1.47) and remained significant after adjusting for potential confounders. These findings were not replicable for the variable neighbourhood SES.

Conclusions: Workplace socioeconomic characteristics, that is, the educational attainment of an individual's colleagues, may influence CHD risk, which represents new knowledge relevant to occupational health management at workplaces.