Longitudinal association of nonrestorative sleep with subjective health and work performance: a cohort study in the Japanese construction industry

Previous studies have reported associations between nonrestorative sleep (NRS) and various physical and mental illnesses. However, its long-term relationship with subjective health and work performance remains unclear. This study aimed to investigate the association between NRS and subjective health and work performance among Japanese workers. A longitudinal cohort study was conducted using health examination and medical claims data from fiscal years 2018 to 2023, involving 36,160 workers. NRS was assessed at baseline based on responses to the question, "Do you feel refreshed after a typical night's sleep?" Longitudinal associations of NRS with subjective physical and mental health and work performance were analyzed using generalized linear models. The prevalence of NRS was 55.4%. NRS was significantly associated with poorer subjective physical health (aOR=1.77, 95% CI: 1.65-1.91) and mental health (aOR=1.66, 95% CI: 1.54-1.79). In addition, workers with NRS exhibited 3.6% lower work performance (95% CI: 3.25-3.88) compared with those with restorative sleep and incurred an estimated annual productivity-related economic loss of approximately JPY 160,000 per worker. These findings indicate that NRS is associated with decreased subjective health and reduced work performance. Early screening and intervention for NRS may help improve workers' health and productivity.