Patients operated on by surgeons with at least 2 hours of social jet lag in the month before surgery had higher rates of major adverse events than those operated on by surgeons with more consistent sleep timing, according to findings published in JAMA Surgery. Because the study was observational, the findings cannot establish that irregular sleep timing caused adverse events.
Researchers evaluated 7,117 operations performed by 38 attending surgeons across 14 surgical departments and 7 specialties at 4 university hospitals in Lyon, France, from November 2020 to December 2021. The surgical specialties included digestive, orthopedic, gynecologic, urologic, cardiac, thoracic, and endocrine surgery. Eligible operations involved adult patients; researchers excluded palliative and organ donation procedures, operations with incomplete operative timestamps, and operations performed by surgeons with invalid sleep data.
Surgeons continuously wore ankle actigraphy devices to measure sleep-wake patterns. Sleep timing regularity during the 30 days before each operation was assessed using social jet lag, defined as the absolute difference between mean midsleep time on workdays and free days. Researchers also assessed midsleep time variability, defined as the standard deviation of daily midsleep times during the same 30-day period. Analyses included only observation windows with at least 17 valid days or nights of accelerometer data.
The primary outcome was the occurrence of at least 1 major adverse event during the operation or within 30 days postoperatively. Events included intraoperative or postoperative inpatient death, postoperative transfer due to organ failure to an intensive care unit for at least 2 nights or to an intermediate care unit for at least 5 nights, unplanned reoperation for complications related to the initial operation, or severe intraoperative or postoperative complications.
Major adverse events occurred in 1,410 operations, or 20%. Severe social jet lag, defined as 2 hours or more, occurred before 342 operations, or 5%, and involved 7 surgeons. Standardized major adverse-event rates were 27% among operations performed by surgeons with severe social jet lag, compared with 20% among operations performed by surgeons with less than 1 hour of social jet lag and 19% among those performed by surgeons with 1 to 2 hours of social jet lag.
After adjustment for surgeon sleep duration during the 24 hours before surgery and across the preceding 30 days, midsleep time, age, sex, professional status, work hours, on-call or night-shift frequency, patient case mix, and incision time, severe social jet lag remained associated with a higher risk of major adverse events. Compared with less than 1 hour of social jet lag, severe social jet lag was associated with a 36% higher adjusted risk of major adverse events. Compared with 1 to 2 hours of social jet lag, severe social jet lag was associated with a 45% higher adjusted risk.
Other sleep measures were not independently associated with major adverse events in adjusted analyses. Midsleep time variability of 60 minutes or more was not associated with adverse outcomes. Sleep duration during the 24 hours before surgery and average sleep duration during the preceding 30 days also were not independently associated with major adverse events.
Researchers also evaluated surgeon burnout using the Maslach Burnout Inventory. Eight surgeons met criteria for burnout, defined as high emotional exhaustion and/or high depersonalization. Surgeons with burnout had higher median social jet lag and greater midsleep time variability than surgeons without burnout. The burnout analysis was limited by the small number of surgeons who met burnout criteria and does not establish temporality or causality.
Several limitations may affect interpretation of the findings. Only 38 of 70 eligible attending surgeons participated, and associate or full professors were overrepresented among participants, which may limit generalizability to community or private practice settings. The study was also conducted in a single geographic region in France. Researchers excluded 2,341 operations with incomplete data, mostly because of missing sleep measurements.
In addition, ankle-worn actigraphy was used because continuous wrist wear was not compatible with sterile operating room protocols. Although the analysis adjusted for multiple surgeon-, patient-, and operation-level factors, residual confounding from unmeasured factors—such as caffeine consumption, sleep-modulating medications, or additional differences in case complexity—cannot be excluded.
In an accompanying invited commentary, Jamie J. Coleman, MD, of the University of Louisville School of Medicine, and Mitchell J. Cohen, MD, of the University of Colorado School of Medicine, wrote that the study adds to emerging evidence that sleep regularity is a distinct component of sleep health. They noted that the findings underscore the complex interplay among sleep duration, sleep timing, burnout, and postoperative complications.
Disclosures: The study was funded by a European Research Council Starting Grant under the European Union’s Horizon 2020 Research and Innovation Program and by the French Ministry of Health. Pascal, Stéphanie Polazzi, MSc, and Antoine Duclos, MD, reported receiving grant support from the European Research Council and/or the French Ministry of Health during the conduct of the study. No other study disclosures were reported. The funders had no role in the design or conduct of the study; data collection, management, analysis, or interpretation; manuscript preparation, review, or approval; or the decision to submit the manuscript for publication. In the invited commentary, Cohen reported receiving grants from the National Institutes of Health outside the submitted work. No other disclosures were reported.
Source: JAMA Surgery
