Association between ensuring a daily rest period in the workplace and workers' sleep: Evidence from a matched employer-employee survey in Japan

OBJECTIVES: This study examined how ensuring a daily rest period (DRP) in the workplace was associated with workers' sleep and whether workplace-level DRPs moderated the association between working hours and sleep, with the exploratory aim of identifying potential differences based on gender. METHODS: Using cross-sectional data from a matched employer-employee survey, this study analyzed a sample consisting of 4202 full-time workers from 2121 workplaces. Logistic regression models were employed to predict sleep quantity and quality outcomes. RESULTS: There was no significant association between ensuring a DRP in the workplace and short sleep duration among full-time workers. Increasing working hours was significantly associated with higher odds of short sleep duration; however, this association appeared weaker among workers in workplaces with ≥11 h DRP. Exploratory analyses stratified by gender suggested that this pattern appeared more evident among women than among men. Moreover, ensuring ≥11 h DRP was significantly associated with lower odds of short sleep duration among overtime workers and daytime sleepiness among full-time workers. Gender-specific differences in insufficient sleep, early morning awakening, daytime sleepiness, and nonrestorative sleep were observed. CONCLUSIONS: The findings suggest the relevance of introducing a work-interval system or taking measures to ensure a DRP in the workplace for workers' sleep health. Nevertheless, further longitudinal, interventional, or quasi-experimental studies are required to establish the causal relationship between ensuring a DRP and sleep outcomes.