Studies Document Danger of Medical Residents’ Sleep Deprivation
First-year medical residents who work 80-hour weeks -- including some 24-hour shifts -- make "significantly more serious medical errors" and have more "lapses in attention" because of fatigue than those who worked fewer hours and got more sleep, according to two studies published in Thursday's New England Journal of Medicine, the Wall Street Journal reports. For the studies, investigators at Brigham and Women's Hospital in Boston and investigators from the Harvard University Work Hours, Health and Safety Study Group compared the work schedules of residents working in intensive-care and cardiac-care units (Landro, Wall Street Journal, 10/28).
Researchers observed residents over a six-week period. During the first three weeks, residents worked a traditional, 80-hour schedule -- the maximum medical residents can work under guidelines implemented last year by the Accreditation Council of Graduate Medical Education. Every three days, residents worked a 24- to 30-hour shift. For another three weeks, residents worked under a modified schedule in which another resident was added to the rotation and two residents worked the overnight shift. Under the modified schedule, residents slept an extra six hours per week and worked about 60 hours total.
For one study, researchers compared the medical-error rates for residents working the traditional and modified schedules. They found that those working worked 24 to 34 consecutive hours every three days committed 35% more serious medical errors than when they worked a maximum of 17 hours. Overall, residents working longer shifts had 136 serious errors for every 1,000 patient days, compared with 100 errors per 1,000 patient days on the shorter shifts (Kowalczyk, Boston Globe, 10/28).
Errors included misdiagnosing patients, ordering the wrong medication or dose, incorrectly interpreting test results or making a mistake during a procedure. According to the AP/Detroit Free Press, there was no significant difference in patient deaths when residents worked longer shifts or shorter shifts, largely because other doctors and nurses monitored residents during the study and caught and corrected many of the errors (AP/Detroit Free Press, 10/28). An abstract of the study is available online.
In the second study, researchers attached 10 electrodes to the heads of the residents to measure drowsiness both during and after work shifts. Monitors attached to the electrodes recorded more than twice as many instances of "profound fatigue" during night shifts -- including eyes rolling back into the head and nodding off -- in residents working the longer schedule, according to the Globe (Boston Globe, 10/28). An abstract of the study is available online.
The research is the first trial specifically designed to compare traditional work schedules with shorter schedules, according to the Journal (Wall Street Journal, 10/28). According to the researchers, the studies show that, in addition to limiting the total number of hours residents should work, more attention should be paid to the length of the shifts" (Boston Globe, 10/28).
"What our study found is that once a certain biological threshold has been crossed," the benefit to patients of having a doctor who has "knows the patient better" is outweighed by the problems of sleep deprivation, Christopher Landrigan, lead researcher on the first study, said. Charles Czeisler, a study co-author, said, "Our study challenges the notion that it's safe to deliver patient care" after working 30 consecutive hours (Stein, Washington Post, 10/28).
In an accompanying editorial, NEJM Editor Jeffrey Drazen, who worked as an attending physician during the studies, raised concerns about the shorter shifts, noting that the residents "knew very little about patients admitted the night before they came on duty." Drazen, who called the existing system flawed, said that hospitals should find ways to provide residents with more complete information about patients' histories as they move to shorter shifts (Boston Globe, 10/28).
Lucian Leape -- a health care quality expert at the Harvard School of Public Health who co-authored a landmark 1999 Institute of Medicine study that showed as many as 98,000 U.S. residents die annually because of hospital errors -- said, "What we have here is the smoking gun." He added, "People have said over and over that a lack of sleep does not inhibit doctor performance. This if the first rigorous study that shows that it does. This is a landmark study."
David Leach, executive director of the ACGME, said the studies' findings "may call for a further refinement of our standards." However, he warned that the "situation is more complicated than just one variable," adding, "I don't know if it's as simple as reducing hours. We could end up doing more harm than good" (Washington Post, 10/28). Andy Whittemore, chief medical officer at Brigham and Women's, noted that the hospital recently began prohibiting all residents who have been on duty 24 hours or longer from writing prescriptions (Boston Globe, 10/28).
In related news, the World Health Organization on Wednesday launched the World Alliance for Patient Safety, an initiative designed to help create a "culture of safety" in health care around the world. According to WHO officials, one in 10 hospital patients worldwide experience a preventable medical error. The initiative seeks to reduce the error rate by allowing scientists and researchers to collaborate on implementing strategies and practices. The United States, Britain and Australia are among the nations participating in the effort.
"Human error is inevitable," Sir Liam Donaldson, chief medical officer of the British Department of Health and chair of the WHO coalition on patient safety, said. He added, "We can reduce error, but most importantly, we can reduce its impact." WHO Director-General Lee Jong-wook said, "Improved health care is perhaps humanity's greatest achievement of the last 100 years. Improving patient safety in clinics and hospitals is in many cases the best way there is to protect the advances we have made in health care" (Kumar, AP/Las Vegas Sun, 10/27).
NBC's "Nightly News" on Wednesday reported on the studies. The segment includes comments from Czeisler and Dr. Aaron Kesselheim, a physician who participated in one of the studies (Bazell, "Nightly News," NBC, 10/27). The complete segment is available online in Windows Media. NPR's "All Things Considered" on Wednesday also reported on the studies. The segment includes comments from Eugene Braunwald, professor of medicine at Harvard and author of physician training textbooks; Czeisler; Drazen; and Kesselheim (Gotbaum, "All Things Considered," NPR, 10/27). The complete segment is available online in RealPlayer.
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