Associations between work style and sleep health indicators among Japanese workers: a comparison by chronotype

Working from home (WFH) is considered beneficial for sleep and fatigue recovery; however, it may vary according to chronotype. In this study, we aimed to assess the relationship between work style, sleep, and health, focusing on different chronotypes. A total of 1,114 workers completed an anonymous online survey, and 587 adult workers were included in the study. Changes in sleep and health indicators were compared by chronotype between the periods when participants worked at the workplace (WAW) every day and WFH two days or more a week. During the WFH period, sleep duration was longer and insomnia level was lower for all chronotypes than that during the WAW period. Evening chronotypes had higher risks of insomnia, poor mental health, and poor fatigue recovery during WAW than did morning chronotypes. However, regarding mental health impairment, the relationship by chronotype disappeared during the WFH period. WFH two days or more a week may provide benefits with respect to sleep and fatigue recovery, regardless of chronotype, particularly for mental health of evening chronotype; however, evening chronotypes had lower level of sleep and health than did other chronotypes, regardless of work style.