The study provides strong support for associations between psychosocial work characteristics and fatigue in men and women, even after adjustment for psychological distress. Moreover, it suggests some differential effects of psychosocial work characteristics on fatigue and psychological distress.

The objective of this study was to assess the predictive value of fatigue for work disability on medical grounds within the framework of a large prospective cohort study. Analyses were carried out on the data of 10 927 employees with a follow up of 32 months. We found that fatigue, as measured with the Checklist Individual Strength, was a strong predictor of subsequent permanent work disability. The for age, gender, presence of a chronic medical condition, and educational level adjusted relative risks were, for the 2nd, 3rd, and 4th fatigue score quartile against the first, respectively: 2.17 (1.17–4.03), 3.30 (1.67–6.52), and 12.8 (5.14–32.1).

The present study investigated work-related determinants of return to work. Our hypothesis was based on the strain hypothesis of the Demand-Control-Support model, which postulates a relation between job demands, job control and support at work on the one hand, and the aetiology of health complaints on the other hand. High demands were hypothesized to obstruct return to work, whereas high control and high support were thought to have a positive effect on return to work. This hypothesis was tested in a population of employees who were sick-listed for 6-8 weeks. Return to work, as operationalized by the categories (i) not working; (ii) return to work with adjustments; and (iii) full return to work, was determined 4 months after the onset of the sick leave. The hypothesis was tested by logistic regression analyses. High job demands were the least predictive of full return to work. However, the likelihood of employees with high job demands returning to work with adjustments was higher than the likelihood of them not working. Therefore, job demands might also work as a pressure to return to work (compare this with Smulders and Nijhuis, 1999). Furthermore, high skill discretion in combination with high job demands predicted working with adjustments in comparison with not working. Finally, high supervisor support was the most predictive of return to work without adjustments, and the least predictive of not working.