Job strain among blue-collar and white-collar employees as a determinant of total mortality: a 28-year population-based follow-up

OBJECTIVES: To investigate the effect of job demand, job control and job strain on total mortality among white-collar and blue-collar employees working in the public sector. DESIGN: 28-year prospective population-based follow-up. SETTING: Several municipals in Finland. PARTICIPANTS: 5731 public sector employees from the Finnish Longitudinal Study on Municipal Employees Study aged 44–58 years at baseline. OUTCOMES: Total mortality from 1981 to 2009 among individuals with complete data on job strain in midlife, categorised according to job demand and job control: high job strain (high job demands and low job control), active job (high job demand and high job control), passive job (low job demand and low job control) and low job strain (low job demand and high job control). RESULTS: 1836 persons died during the follow-up. Low job control among men increased (age-adjusted HR 1.26, 95% CI 1.12 to 1.42) and high job demand among women decreased the risk for total mortality HR 0.82 (95% CI 0.71 to 0.95). Adjustment for occupational group, lifestyle and health factors attenuated the association for men. In the analyses stratified by occupational group, high job strain increased the risk of mortality among white-collar men (HR 1.52, 95% CI 1.09 to 2.13) and passive job among blue-collar men (HR 1.28, 95% CI 1.05 to 1.47) compared with men with low job strain. Adjustment for lifestyle and health factors attenuated the risks. Among white-collar women having an active job decreased the risk for mortality (HR 0.78, 95% CI 0.60 to 1.00). CONCLUSION: The impact of job strain on mortality was different according to gender and occupational group among middle-aged public sector employees.