This prospective study examined effort-reward imbalance (ERI), a recent measure of work stress, as a risk factor for disability pension. To minimize subjectivity bias, work unit-level scores of ERI were used. High ERI was associated with an increased risk of disability pension due to depression but not musculoskeletal or cardiovascular diseases.

Objectives The aim of this study was to examine the association between co-occurring work stressors and risk of disability pension. Methods The work stressors job strain, effort-reward imbalance (ERI), and organizational injustice were measured by a survey in 2008 of 41 862 employees linked to national records of all-cause and cause-specific disability pensions until 2011. Co-occurring work stressors were examined as risk factors of work disability using Cox regression marginal models. Results Work stressors were clustered: 50.8% had no work stressors [observed-to-expected ratio (O/E)=1.2], 27.4% were exposed to one stressor (O/E=0.61-0.81), 17.7% to two stressors (O/E=0.91-1.73) and 6.4% to all three stressors (O/E=2.59). During a mean follow-up of 3.1 years, 976 disability pensions were granted. Compared to employees with no work stressors, those with (i) co-occurring strain and ERI or (ii) strain, ERI and injustice had a 1.9-2.1-fold [95% confidence interval (CI) 1.7-2.6] increased risk of disability retirement. The corresponding hazard ratios were 1.2 and 1.5 (95% CI 1.0-1.8) for strain and ERI alone. Risk of disability pension from depressive disorders was 4.4-4.7-fold (95% CI 2.4-8.0) for combinations of strain+ERI and strain+ERI+injustice, and 1.9-2.5-fold (95% CI 1.1-4.0) for strain and ERI alone. For musculoskeletal disorders, disability risk was 1.6-1.9-fold (95% CI 1.3-2.3) for strain+ERI and ERI+injustice combinations, and 1.3-fold (95% CI 1.0-1.7) for strain alone. Supplementary analyses with work stressors determined using work-unit aggregates supported these findings. Conclusions Work stressors tend to cluster in the same individuals. The highest risk of disability pension was observed among those with work stressor combinations strain+ERI or strain+ERI+injustice, rather than for those with single stressors.

Supervisors` fair treatment of employees and fair decision-making in the organizations are associated with a decreased risk of disability pensioning from all-causes, depression and musculoskeletal diseases. These associations may be attributable to a wider range of favorable work characteristics.