Job exposures, employer characteristics, and risk of reduced work capacity: a 10-year cohort study of Norwegian workers

OBJECTIVE: This study investigates the impact of biomechanical and psychosocial job exposures on risk of reduced work capacity in a complete cohort of Norwegian workers, and examines whether this impact varies by employer sector, size, and organizational policies. METHODS: Using high-quality Norwegian registry data, we followed a cohort of workers from age 40 over a ten-year period. Biomechanical and psychosocial job exposures were estimated using two validated job exposure matrices. Individuals with a prior history of reduced work capacity were excluded to limit confounding. Using Cox proportional hazard models, we assessed the association between levels of job exposure and risk of reduced work capacity, including moderation analyses by employer characteristics. RESULTS: Both biomechanical and psychosocial job exposures were significantly associated with reduced work capacity, particularly among the top 60% of exposed workers. While employer size and organizational policies somewhat moderated this impact, their influence was inconsistent. Notably, policies aimed at retaining workers with reduced capacity did not appear to mitigate the impact of the job exposures, while there was no variation in impact according to employer sector. CONCLUSION: Biomechanical and psychosocial job exposures are associated with an increased risk of reduced work capacity, with some variation in impact according to employer characteristics. These results indicate the importance of exposure-reducing interventions in the workplace, especially in occupations with high levels of biomechanical and psychosocial exposures.