Physical and psychosocial working conditions as explanations for occupational class inequalities in self-rated health.

BACKGROUND Socio-economic health inequalities are well documented, but efforts to explain health inequalities are less. However, previous studies suggest that working conditions provide potential explanations for inequalities in health. METHODS Cross-sectional questionnaire survey data, collected from municipal employees of the City of Helsinki, aged 40-60 years (n = 8960, response rate 67%) in 2000-02, were examined using binomial regression analysis. Socio-economic position was measured by six occupational social classes ranging from top managers to manual workers, and the outcome was self-rated health (SRH). Key physical and psychosocial working conditions and work arrangements were included as explanatory factors for inequalities in health. RESULTS Occupational class inequalities in SRH were clear among women [prevalence ratio (PR) 1.89, 95% confidence interval (CI) 1.54-2.32] and men (PR 1.78, 95% CI 1.40-2.25). Heavy physical workload explained a half of the health inequalities among women and almost one-third among men. Physical and chemical exposures at work explained one-fifth of the health inequalities among women and a half among men. Job control explained 24% of the men's and 40% of women's inequalities, whereas job demands widened the inequalities by 13-14%. The effects of shift work and working hours were negligible. In the fully adjusted model, 60% of the women's and 32% of the men's inequalities in SRH were explained. CONCLUSION Physical working conditions explained a large part and job control, a somewhat smaller part of socio-economic inequalities in SRH. Improving physical working conditions and increasing job control provide potential routes to reduced inequalities in health among employees.