Skip Navigation Archive: U.S. Department of Health and Human Services
Archive: Agency for Healthcare Research Quality
Archive print banner

National Study of Medical Interns Finds Majority Exceed Work Hour Limits; Link Made Between Needle Stick Injuries and Long Shifts

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Press Release Date: September 6, 2006

Nearly 84 percent of medical interns reported that they are continuing to work hours that exceeded the limits of a 2003 national standard implemented by the medical profession, a new study finds. A related study concludes that interns are much more likely to injure themselves mistakenly with a needle or another sharp instrument when working in a hospital more than 20 consecutive hours, or at night.

The studies appear in the September 6, 2006, issue of the Journal of the American Medical Association and were funded by HHS' Agency for Healthcare Research and Quality (AHRQ), the National Institute for Occupational Safety and Health within the Centers for Disease Control and Prevention, and Brigham and Women's Hospital. These findings build on previous research and the growing awareness that sleep-deprived first-year doctors in training (interns) working traditional 24-hour shifts make many more serious medical errors and crash their cars more often than those whose work is limited to 16 consecutive hours.

"These studies raise troubling questions about compliance with standards that were developed to reduce medical errors due to work-hour-related fatigue," said AHRQ Director Carolyn M. Clancy, M.D. "Residency programs that don't comply with these standards could be jeopardizing the safety of both their patients and their interns," she added.

In 2003, the Accreditation Council for Graduate Medical Education (ACGME) introduced work-hour limits for all first-year residents training in U.S. hospitals. Under these standards, interns are limited to a maximum of 30 consecutive work hours (known as the 30-hour rule), which includes time used for sign-out, teaching, and continuity of care. Interns also are prohibited from working more than 80 hours per week (the 80-hour rule), averaged over 4 weeks, and must be free of all duties for 1 day in 7 (the 7-day rule). In the year following implementation of the standards, mandatory reports submitted to the ACGME by residency programs concluded that only 5 percent of residency programs did not comply, and that only 3 percent of residents reported any violations of the 80-hour rule.

However, an independent, nationwide study conducted by researchers at Brigham and Women's Hospital, Boston, found that 83.6 percent of interns reported work hours that did not comply with the ACGME standards during at least one month in the year (July 2003-May 2004) following implementation.

In the study, "Interns' Compliance with Accreditation Council for Graduate Medical Education Work-Hour Limits," Christopher P. Landrigan, M.D., M.P.H., Director of the Sleep and Patient Safety Program at Brigham and Women's Hospital, and colleagues prospectively collected data on interns' work and sleep hours in the year before (June 2002 through May 2003) and after (June 2003 through May 2004) the ACGME standards were implemented. The 4,015 participants completed monthly reports of their work hours and sleep, and they represented residency programs across all specialties.

Study authors offer several reasons why non-compliance with the ACGME work-hour rules may be high. Because the standards were created without taking account of financial or technical implementation, residency programs may not have the resources to redesign their programs appropriately. Non-compliance might also be due to the culture within a particular medical institution. Some senior physicians have expressed disapproval of work-hour limits, while others do not believe fatigue represents a threat to patient safety.

"Current professional regulations allow doctors-in-training to work 24-30 hours in a row, a limit far beyond established safe limits for pilots and truckers, and far beyond the legally enforced 13-hour limit for physicians in Europe," said Dr. Landrigan. "Yet even this permissive limit is routinely exceeded. To address the epidemic of medical errors in this country, we must start by establishing evidence-based, safe work-hour limits for young physicians, and we must then enforce them."

In the second study, "Extended Duration Work and the Risk of Self-Reported Percutaneous Injuries in Interns," researchers found that interns working during the day following an overnight shift suffered 61 percent more needlesticks and other sharp object injuries than they experienced during a day that was preceded by a night at home (1.3 per 1,000 opportunities versus 0.76 per 1,000 opportunities). Furthermore, interns suffered more than twice the rate of injuries during the night (1.48 per 1,000) than during the daytime (0.7 per 1,000). Lapses in concentration and fatigue were the two most commonly reported contributing factors (64 percent and 31 percent respectively). These types of injuries may result in transmission of blood-borne pathogens including hepatitis and HIV.

The study, conducted by researchers at Brigham and Women's Hospital, Boston, and Vancouver General Hospital, Vancouver, British Columbia, surveyed 2,737 interns in U.S. residency programs from July 2002 through May 2003. Dr. Najib Ayas and colleagues collected monthly data on work schedules and the occurrence of injuries with sharp instruments.

"These two studies demonstrate that academic medical centers have not complied with even the very modest restrictions that the medical profession attempted to self-impose on physician work hours, and that excessive work hours continue to endanger seriously both physicians-in-training and their patients," said senior author Charles A. Czeisler, Ph.D., M.D., Chief, Division of Sleep Medicine at Brigham and Women's Hospital and Baldino Professor of Sleep Medicine at Harvard Medical School.

Editor's Note: For further information on sleep deprivation and safety, go to

For more information, please contact AHRQ Public Affairs: (301) 427-1855 or (301) 427-1889.


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care