News Release

National study of resident physicians suggests need for federal work hour guideline changes

The risk of medical errors and preventable adverse events increased when physicians in their second year or above of training worked one or more extended duration shifts in a month

Peer-Reviewed Publication

Brigham and Women's Hospital

The risk of medical errors and preventable adverse events increased when physicians in their second year or above of training worked one or more extended duration shifts in a month

More experience on the job does not protect resident physicians or their patients from the increased safety risks associated with long work weeks and extended-duration work shifts, according to a new study led by investigators from Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system. To date, nationwide workhour guidelines in the United States have largely focused on resident physicians in their first year of residency (known as PGY1), omitting more experienced resident physicians in their second year (PGY2) or beyond (PGY2+). Brigham researchers analyzed national survey results from more experienced resident physicians and found that, much like PGY1 residents, those who worked more hours per week or worked extended-duration shifts reported higher rates of safety events affecting patients, such as medical errors and preventable adverse events, as well as safety events affecting themselves, such as near-miss vehicle crashes and occupational exposures. Results are published in BMJ Medicine.

“More experienced residents need sleep, just like anyone else, and when they work extended shifts or put in long weekly hours, they often do not have the opportunity to get the sleep that they need and are just as susceptible to these risks  as first-year resident physicians,” said corresponding author Laura K. Barger, PhD, of the Division of Sleep and Circadian Disorders in the Departments of Medicine and Neurology. “Our research shines a light on an issue that affects both resident physicians and their patients and should prompt a reexamination of national guidelines.”

In the U.S., the Accreditation Council for Graduate Medical Education (ACGME) set guidelines that went into effect in 2011 limiting first-year resident work shifts to 16 hours or less, based on recommendations made by the National Academy of Medicine and informed by studies conducted by Brigham investigators over the last four decades. But the ACGME endorsed extended-duration work shifts of up to 28 consecutive-hours for more experienced resident physicians and up to 80-hour work weeks for all residents. In countries in the European Union, resident physicians are limited to work 48 hours or less per week.

Barger and colleagues conducted a nationwide prospective cohort study of resident-physicians in the U.S., collecting responses over eight academic years (2002-2007, 2014-2017) from 4,826 resident physicians in their second year or beyond. Survey respondents answered questions about patient safety outcomes and about their own health and safety outcomes.

Even after adjusting for hours spent in patient care, the researchers found that residents who worked more weekly hours or worked extended-duration shifts were at greater risk of making errors that endangered patients or themselves. Working more than 48 weekly work hours was associated with more medical errors, preventable adverse events, as well as near-crashes, occupational exposures, percutaneous injuries, and attentional failures. Risk continued going up for residents working 60, 70 and up to 80-hour work weeks (the current work week limit), with residents exceeding 60 hours of work being more likely to report errors resulting in death to a patient. Weekly work hours at currently permissible limits were associated with approximately three times the risk of a medical error or preventable adverse event, compared to residents working similar hours as those in the European Union.

“Working just one extended-duration shift in a month was associated with increased risk of medical errors as well as having a near-collision on the way home from work,” said co-author Matthew Weaver, PhD, of the Division of Sleep and Circadian Disorders. “The ACGME currently endorses extended-duration work shifts of up to 28 consecutive hours for all residents, which means they are often working without adequate sleep.”

The authors note that their study is based on self-reported data and collected from residents who chose to participate in the survey. But participants were unaware of the study’s focus and questions about safety outcomes were included among others about caffeine usage and physical activity.

In an accompanying editorial, also published in BMJ Medicine, the authors call for national policy changes to limit work hours and extended shifts as well as screening for sleep disorders and providing sleep health education resources for resident physicians.

“The harm of long work weeks and extended shifts affects experienced senior resident physicians in the same way as it does first-year resident physicians and that harm is reaching patients,” said senior author Charles Czeisler, MD, PhD, chief of the Division of Sleep and Circadian Disorders. “In other parts of the world, physicians are effectively trained while working safer hours. Our findings provide further evidence that it is time for guidelines in the U.S. to change to ensure that all resident physicians, regardless of their experience, have safer work-hour limits.”

Disclosures: Dr. Czeisler reports grant support from National Institute of Occupational Safety and Health within the US Centers for Disease Control and Prevention, the Agency for HealthCare Research and Quality, and the National Health Lung and Blood Institute. Prof. Charles Czeisler serves as the incumbent of an endowed professorship provided to Harvard Medical School by Cephalon, Inc. in 2004, which provided institutional support for this work. He has received additional support from Delta Airlines, Jazz Pharmaceuticals PLC Inc., Axome Therapeutics, Inc., Philips Respironics Inc, Puget Sound Pilots, Regeneron Pharmaceuticals and Sanofi SA, ResMed, Teva Pharmaceuticals Industries Ltd and Vanda Pharmaceuticals. Dr. Czeisler receives royalty payments from Phillips Respironics on sales of the Actiwatch-2 and Actiwatch-Spectrum devices. He has received personal consultancy fees from With Deep, Inc. and Vanda Pharmaceuticals. Dr. Czeisler received honoraria from Associated Professional Sleep Societies, Massachusetts Medical Society and the National Sleep Foundation and travel fees from Stanley Ho Medical Development Foundation and Associated Professional Sleep Societies. Dr. Czeisler has equity interest in Vanda Pharmaceuticals, With Deep, Inc. and Signos, Inc. Dr. Czeisler is an Advisory Board member for UK Biotechnology and Biological Sciences Research Council, Institute of Digital Media and Child Development and Klarman Family Foundation. Dr. Czeisler has received educational or research gifts (to Brigham and Women’s Hospital) from Johnson & Johnson, Mary Ann and Stanley Snider via Combined Jewish Philanthropies, Alexandra Drane, DR Capital Management, LLC, Harmony Biosciences LLC, Vanda Pharmaceuticals, Inc, Eisai Co., LTD,  Jazz Pharmaceuticals, Idorsia Pharmaceuticals LTD, Sleep Number Corp., Apnimed, Inc., Avadel Pharmaceuticals, Axome Therapeutics, Inc., Bryte Foundation, f.lux Software, LLC, Stuart F. and Diana L. Quan Charitable Fund, Casey Feldman Foundation, Roman Catholic Archdiocese of Boston, Summus, Inc., Takeda Pharmaceutical Co., LTD, Philips Respironics, Abbaszadeh Foundation, Sharon and John Loeb, CDC Foundation, Centers for Disease Control and Prevention and ResMed, Inc. A full list of disclosures can be found in the paper.

Funding: This study was supported by grants from the National Institute for Occupational Safety and Health (NIOSH) within the U.S. Centers for Disease Control (1 R01 OH07567 1 R01 OH010300, 1 R01OH011773)   and by the Agency for Healthcare Research and Quality (R01 HS12032), the National Heart, Lung and Blood Institute (T32 HL079010, U01 HL111478 and R56 HL151637).

Paper cited: Barger LK et al. “Impact of Work Schedules on Patient and Resident Physician Safety in Post Graduate Year 2 and Higher” BMJ Medicine DOI: 10.1136/bmjmed-2022-000320


About Mass General Brigham

Mass General Brigham is an integrated academic health care system, uniting great minds in medicine to make life-changing impact for patients in our communities and people around the world.

Mass General Brigham connects a full continuum of care across a system of academic medical centers, community and specialty hospitals, a health insurance plan, physician networks, community health centers, home care, and long-term care services. 

Mass General Brigham is a non-profit organization that is committed to patient care, research, teaching, and service to the community. In addition, Mass General Brigham is one of the nation’s leading biomedical research organizations and a principal teaching affiliate of Harvard Medical School. For more information, please visit

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.