Joint association of daily rest periods and sleep duration with sick leave: a one-year prospective cohort study of daytime employees in Japan.

Daily rest period (DRP) refers to the interval between the end of one workday and the start of the next. This study examined the joint association of DRP and sleep duration with subsequent sick leave among Japanese daytime employees. Participants (n=5,593) were measured for DRP and sleep duration at baseline and for sick leave at 1-year follow-up. They were categorized into 10 groups based on their DRP and daily sleep duration. Logistic regression analyses for individuals experiencing sick leave for longer than a month showed that the combination of short DRP (<11 h) and sleep duration (<6 h) had a higher odds ratio (4.981, 95% confidence interval [CI] = 1.126-22.046) than the reference group. Furthermore, the combination of short DRP and normal sleep duration had a higher odds ratio (8.152, 95% CI = 1.801-36.902) than the reference group. Short DRP was associated with subsequent long sick leave.