NAGAMINE Daiki    Department   School of Medicine, School of Medicine    Position   Assistant Professor
Article types	Original article
Language	Japanese
Peer review	Peer reviewed
Title	Sleep duration and subjective fatigue among hospital physicians during night shifts
Journal	Formal name：The Journal of Science of Labour ISSN code：0022-443X
Domestic / Foregin	Domestic
Volume, Issue, Page	pp.85-92
Author and coauthor	Shinji Yamaguchi†, Minako Koike, Daiki Nagamine, Takako Miki, Michiko Nohara*
Publication date	2025/12/10
Summary	This study aimed to assess the actual conditions of sleep duration and fatigue among physicians during night shifts, using a wearable device to measure their sleep. The study was conducter from February to September 2023 and included 13 physicians (8 males, 5 females, mean age 34.2 ± 7.0 years) working at hospitals in the Kanto region. Sleep duration was measured using the Fitbit Inspire 2, while subjective fatigue was assessed with the subjective fatigue questionnaire Jikaku-sho Shirabe. Participants wore the Fitbit Inspire 2 during night shifts and completed the questionnaire before and after sleeping. During the night shifts, the longest recorded sleep duration was 504 minutes, the shortest was 26 minutes, and the mean sleep duration was 232 minutes. Five participants experienced sleep durations of less than 120 minutes on 10 occasions in total. Correlational analyses between sleep duration and changes in fatigue scores showed no statistically significant associations overall (within-individual correlation: r = .02, p = .97; between-individual correlation: r = –.51, p = .07). However, for some participants, longer sleep duration tended to be associated with greater reduction in fatigue. These findings suggest that visualizing one’s own sleep and fatigue data may promote physicians’ self-understanding and self-management, potentially supporting healthier work styles in the future.