Disturbed sleep and fatigue as predictors of return from long-term sickness absence

Long-term sickness absence has doubled in Sweden, as has complaints of disturbed sleep. The present study sought to investigate the prospective link between long-term sickness absence and disturbed sleep or fatigue. Sleep and fatigue from a representative national sample was followed up 1.5-2 yr later in terms of return from long-term (>or=90 d) and intermediate term (14-89 d) sickness absence. 8,300 individuals participated in the survey, out of which 372 were on long-term and 1,423 were on intermediate term sick leave. The data was analyzed using logistic regression analysis with adjustment for background and work environment variables. Separate analyses were carried out for disturbed sleep and fatigue since they were correlated. The results showed that those with disturbed sleep at the start had an Odds Ratio (OR) of 0.56 (95% Confidence Interval (CI)=0.35-0.90) for returning from long-term sickness absence. For fatigue the results were OR=0.56 (CI=0.34-0.90). Intermediate term sickness absence showed similar, but slightly weaker, results. The results indicate that disturbed sleep and fatigue are predictors of lack of return from long term and intermediate term sickness absence.