OBJECTIVE: This cross-sectional study examined the impact of family cohabitation status and work-from-home (WFH) on sleep during the COVID-19 pandemic. METHODS: An online survey of 27,036 Japanese workers assessed WFH frequency, family cohabitation, and trouble sleeping to estimate odds ratios (ORs) for sleep problems from December 22 to 26, 2020. RESULTS: In multivariate analysis, WFH had no significant benefit for trouble sleeping ≥3 months. Interactions were observed between WFH and cohabitation with elementary school children (OR = 1.26, P = 0.049 for trouble sleeping ≥3 months) and with family members in need of care (OR = 1.39, P = 0.013 for trouble sleeping ≥3 days/week
OR = 1.37, P = 0.02 for trouble sleeping ≥3 months). CONCLUSIONS: The study suggests that the sleep disadvantage during the pandemic may have resulted from WFH with specific cohabitation.