Fatigue and risk of sickness absence in the working population: A systematic review and meta-analysis of longitudinal studies.

Objectives Fatigue, a common complaint in workers, has been related to sickness absence (SA). The purpose of this systematic review and meta-analysis was to determine the prospective association between fatigue and SA in the working population. Methods An electronic literature search was conducted in five databases: PubMed, Embase, CINAHL, Psyc-INFO and Cochrane CENTRAL. Longitudinal studies were selected that focused on fatigue and future SA in workers. Random-effects meta-analyses were conducted and pooled estimates [95% confidence intervals (CI)] were obtained for the association between fatigue and risk of long-term SA in total and by sex. Heterogeneity was assessed by I 2statistics. Results Of the 16 included studies in the review, 14 provided supportive evidence for an association between fatigue and SA. The meta-analysis of 9 studies (provided 15 estimates) that were mostly of high quality showed that baseline fatigue increased the risk of long-term SA by 35% (95%CI 1.23-1.47) in workers. Heterogeneity was low-moderate (I 2=40%). The pooled estimates for an increased risk for long-term SA were 35% (95% CI 1.18-1.54) in fatigued men and 22% (95% CI 0.93-1.60) in fatigued women however this relationship was not statistically significant. Conclusion There is conclusive evidence for the prospective association between worker fatigue and long-term SA. Whereas most studies in the review measured chronic fatigue and long-term SA, there was insufficient data for the meta-analysis to draw conclusions on fatigue type. Future research is needed in this area as well as greater exploration of fatigue and long-term SA in women.