Sleep, Well-Being, and Cognition in Medical Interns on a Float or Overnight Call Schedule

• Published in: JAMA network open 2024-10, Vol.7 (10), p.e2438350
• Main Authors: Massar, Stijn A A, Chua, Xin Yu, Leong, Ruth, Golkashani, Hosein A, Pu, Zhenghao, Ng, Alyssa S C, Ong, Ju Lynn, Soon, Chun Siong, Ng, Nicholas B H, Tan, Mae Yue, Lin, Jeremy B, Aw, Marion, Chee, Michael W L
• Format: Article
• Language: English
• Subjects: Adult; Cognition & reasoning; Cognition - physiology; Cohort analysis; Female; Humans; Internship and Residency; Longitudinal Studies; Male; Medical Education; Online Only; Original Investigation; Schedules; Shift work; Shift Work Schedule; Singapore; Sleep; Sleep - physiology; Work Schedule Tolerance - psychology; Working hours
• ISSN: 2574-3805; 2574-3805
• DOI: 10.1001/jamanetworkopen.2024.38350

Extended work hours and night shifts are essential in health care, but negatively affect physician sleep, well-being, and patient care. Alternative schedules with shorter work hours and/or reduced irregularity might mitigate these issues. To compare sleep, well-being, and cognition between interns working irregular, extended shifts (call schedule), and those working a more regular schedule with restricted hours (float schedule). In this observational longitudinal cohort study, interns in a Singapore-based teaching hospital were studied for 8 weeks from January 2022 to July 2023. Data were analyzed from July 2023 to July 2024. Participants worked either regular approximately 10-hour workdays, interspersed with 24 hour or more overnight calls 4 to 5 times a month, or a float schedule, which included regular approximately 10-hour workdays, and 5 to 7 consecutive approximately 12-hour night shifts every 2 months. Exposure was based on departmental training and operational needs. Sleep was measured with wearable sleep trackers and an electronic diary. Day-to-day well-being and cognitive assessments were collected through a smartphone application. Assessments included the Sleep Regularity Index (SRI; determines the probability of an individual being in the same state [sleep or wake] at any 2 time points 24 hours apart, with 0 indicating highly random sleep patterns and 100 denoting perfect regularity) and Pittsburgh Sleep Quality Inventory (PSQI; scores ranges from 0 to 21, with higher scores indicating poorer sleep; a score greater than 5 suggests significant sleep difficulties). Participants (mean [SD] age, 24.7 [1.1] years; 57 female participants [59.4%]; 41 on call schedule [42.7%]; 55 on float schedule [57.3%]) provided 4808 nights of sleep (84.2%) and 3390 days (59.3%) of well-being and cognition assessments. Participants on a float schedule had higher SRI scores (mean [SD] score, 69.4 [6.16]) and had better quality sleep (PSQI mean [SD] score, 5.4 [2.3]), than participants on call schedules (SRI mean [SD] score, 56.1 [11.3]; t91 = 6.81; mean difference, 13.3; 95% CI, 9.40 to 17.22; P