November 12, 2004
The State of HSPH:
Gene Expression Profile Predicts Survival in Ovarian Cancer
Birth of Motor Neurons Connected to Spinal Cord Induced in Adult Brain
Five from HMS and HSPH Appointed to IOM
Grants Advance Research on Childhood Brain Tumors
Talking to the Public: How Can Media Coverage of Medicine Be Improved?
Extended Shifts for Residents Called Risky for PatientsAfter 10 hours on the job, a truck driver must pull off the road. After 16 hours, an airline pilot can no longer legally fly a plane. But after 24 hours or more on the job, with perhaps an hour nap somewhere along the line, a first-year medical resident can perform a surgical procedure, write a prescription, or insert a chest tube.
"Having grown up in the medical culture, even we were surprised" that interns made 35.9 percent more medical errors considered serious, including more than five times as many serious diagnostic errors when they worked a schedule with 30-hour shifts, said Charles Czeisler (left), with Christopher Landrigan. (Photo by Graham Ramsay)
How much sleep is too little? It's a question that has plagued teaching hospitals for years and an issue that seemed to be at least temporarily resolved last year when the Accreditation Council for Graduate Medical Education (ACGME) created standards limiting residents' hours to 80 per week. But two articles in the Oct. 28 New England Journal of Medicine have brought the issue back to light. The studies show that the 80-hour workweek still causes significant fatigue and errors in first-year residents. The HMS researchers, led by Charles Czeisler, the Frank Baldino Jr., PhD professor of sleep medicine at Brigham and Women's Hospital, showed that an intervention cutting shift times in half reduced signs of fatigue in interns as well as serious medical errors in patient care.
Though current guidelines limit the total number of hours per week that interns work, they still allow long shifts that can stretch to 30 hours. The researchers studied the effect of shortening both total hours worked and shift length. In one study, led by Steven Lockley, HMS instructor in medicine at BWH, 20 interns completed two three-week rotations in the intensive care unit at BWH. One rotation followed a traditional schedule--shifts of at least 30 hours every other shift, alternating with day shifts of approximately 10 hours (a "q3" schedule in hospital parlance). In practice, shifts tended to carry beyond their allotted time; nearly all interns worked 80 or more hours per week. On the intervention schedule, the extended shift was cut in half, limiting scheduled work to 16 consecutive hours, for a total of around 65 hours per week.
The interns logged the hours they spent sleeping and were monitored at work and at home with electrodes to record eye movements and brain waves. On the intervention schedule, interns averaged 5.8 hours more sleep per week and experienced less than half the rate of "attentional failures" at night, slow-rolling eye movements caused by profound sleepiness during waking activities at work.
Czeisler, who heads the HMS Division of Sleep Medicine, said that people outside the medical profession cannot believe the results are news. A 2002 National Sleep Foundation poll found that 86 percent of people would fear for their safety if they knew their doctor had been awake for 24 consecutive hours. He attributes the contrasting views in part to a kind of "siege mentality" in medicine that prizes the heroics of staying up late with patients.
"When the residency system was originally designed, the idea was that you would be available in the hospital for overnight emergencies, but you would not actually be working the entire time," Landrigan said. But as the number of patients passing through hospitals has risen and hospital stays have shortened, residents now often spend their entire shifts working, frequently with no sleep at all. The cost and complexity of adding personnel has kept even sympathetic hospitals from relieving the residents' burden.
Beyond economics and a culture of sleeplessness among physicians, many people have worried that limiting shift lengths for residents may actually harm patients. A 1994 study at BWH tracked medical errors in the hospital and found that patients were six times as likely to have an adverse event when they were cross-covered by a different doctor because of the loss of continuity in care when patients are handed from person to person.
David Bates, HMS professor of medicine at BWH and one of the Landrigan study authors, pointed out that a computerized patient sign-off system at BWH has subsequently reduced the errors caused by cross-coverage. The Landrigan study found that even with more patient handoffs, fewer errors occurred when interns were better rested. Bates said that it "demonstrates empirically for the first time what the effect of fatigue is on error rates," giving support to the argument that long shifts harm patients.
Many hospitals have reduced total hours by simply extending interns' time off between extended shifts, but Czeisler and Landrigan believe that it is never healthy to work an extended shift. "The 30-hour shift is an absolutely sacrosanct component of medical education," Czeisler said. "This study suggests that that tradition, which has been accepted without question, may itself pose a hazard to patient safety."
Both of the NEJM papers are available at http://workhours.bwh.harvard.edu, where users can also report safety problems related to sleep deprivation.
Part two of this story, in the Dec. 3 Focus, will look at how residency programs at BWH and other Harvard-affiliated hospitals have implemented new guidelines to address these safety issues and adjust to new restrictions on residents' hours.