Association of work-time control with sickness absence due to musculoskeletal and mental disorders: An occupational cohort study.

OBJECTIVES:Work-time control is associated with lower sickness absence rates, but it remains unclear whether this association differs by type of diagnosis and sub-dimension of work-time control (control over daily hours and control over time off) and whether certain vulnerable groups benefit more from higher levels of work-time control. METHODS:Survey data from the Finnish 10-town study in 2004 were used to examine if baseline levels of work-time control were associated with register data on diagnose-specific sickness absence for 7 consecutive years (n = 22 599). Cox proportional hazard models were conducted, adjusted for age, sex, education, occupational status, shift work including nights, and physical/mental workload. RESULTS:During follow-up, 2,818 individuals were on sick leave (≥10 days) due to musculoskeletal disorders and 1724 due to mental disorders. Employees with high (HR = 0.80, 95% CI 0.74-0.87; HR = 0.76, 95% CI 0.70-0.82, respectively) and moderate (HR = 0.83, 95% CI 0.77-0.90; HR = 0.85, 95% CI 0.79-0.91, respectively) levels of control over daily hours/control over time off had a decreased risk of sickness absence due to musculoskeletal disorders. Sub-group analyses revealed that especially workers who were older benefitted the most from higher levels of work-time control. Neither sub-dimension of work-time control was related to sickness absence due to mental disorders. CONCLUSIONS:Over a 7-year period of follow-up, high and moderate levels of work-time control were related to lower rates of sickness absence due to musculoskeletal disorders, but not due to mental disorders.