Purpose: Prolonged fatigue adversely affects an individual's performance and functioning. The present study investigated the prospective associations between prolonged fatigue and sickness absence (SA) during 1-year follow-up.
Methods: At baseline, a convenience sample of white-collar employees received the 20-item Checklist Individual Strength (CIS), which measures prolonged fatigue by covering the dimensions fatigue severity, reduced concentration, reduced motivation, and reduced physical activity. SA episodes were registered during the 1-year follow-up distinguishing between short-term (1-7 days) and long-term ( 7 days) SA episodes. Baseline CIS scores were linked to SA during follow-up by negative binomial regression models in which age, gender, job grade, and prior SA were controlled for.
Results: Six hundred and thirty-three (56 %) employees participated in the study of which 598 had complete data and were eligible for analysis. Gender was a significant effect modifier of the relationship between prolonged fatigue and SA. Therefore, the results were stratified for men (N = 365) and women (N = 233). In white-collar men, fatigue severity and reduced concentration were positively associated with the number of long-term SA episodes, while other fatigue dimensions were not significantly related to SA. In white-collar women, prolonged fatigue was not associated with SA during 1-year follow-up.
Conclusion: The results of this study warrant more attention for prolonged fatigue in occupational healthcare practice and research. Early identification of and treatment for prolonged fatigue might prevent future health problems and SA, especially in white-collar men.