WEDNESDAY, Jan. 12, 2005 (HealthDayNews) -- Young doctors-in-training who work the long shifts required by most hospitals are so woozy when they drive home, they run the same risk of a car accident as someone who is legally drunk, a new Harvard study finds.
The nationwide survey of 2,737 interns found the chance of having an accident on the road more than doubled after a work shift of 32 hours, while the risk of a near miss increased nearly sixfold.
Yet "these interns are forced by hospitals to work marathon shifts," said study author Dr. Charles A. Czeisler, chief of the sleep medicine division at Brigham and Women's Hospital, Harvard University's teaching hospital. "They can't get a medical license or board certification if they don't do it."
The findings appear in the Jan. 13 issue of the New England Journal of Medicine.
The report is a follow-up to a previous study that found that Brigham and Women's interns on the traditional schedule of more than 80 hours a week -- with some shifts longer than 24 hours -- made 35.9 percent more medical errors than those working a less demanding schedule of fewer than 80 hours a week, with no shift longer than 16 hours.
The hospital announced at that time that it would put a 16-hour limit on the shifts for doctors in training.
It has been assumed that interns get time to sleep several hours while they are on the extended shifts, Czeisler said. But the pressure of modern medicine, which requires extensive work-ups for most patients and puts a premium on getting patients out of the hospital as quickly as possible, limits the doctors to catnaps that provide little relief from strain, he said.
"We found that they spent 96 percent of their time awake," Czeisler said. "We don't realize the dramatic change in the extent to which they have lost the opportunity to sleep."
A telling indicator of the magnitude of the problem is the journal's choice to have an accompanying editorial written by C. Dennis Wylie, a self-described "human factors scientist" who has spent 35 years working on highway safety problems such as those encountered by truck drivers.
Wylie's work was instrumental in adoption of 2003 federal regulations that increased the required off-duty time for truck drivers from eight hours to 10 hours in every 24-hour period.
The Harvard study, he said, shows that "if doctors were drivers, they are so far beyond current work-hour limits that if they were caught, they would be barred from driving. The fact that they have more than twice the risk of crashing hits you right between the eyes."
Studies have shown that 17 hours without sleep decreased performance on a test of psychomotor ability as much as a blood alcohol content of 0.05 percent, Wylie said. And 21 hours of wakefulness affected performance as much as a blood alcohol content of 0.08 percent. The U.S. legal limit for blood alcohol content for commercial drivers is 0.04 percent and for most ordinary drivers it is 0.08 percent, he said.
Wylie added that any comment on the effect of long hours of sleeplessness on a doctor's performance in a hospital "is outside my competence."
"I will not make specific suggestions because I am not familiar with physician training," he said. "I can say for sure that they are not getting enough sleep."
More information
For more on medical training programs for interns, visit the Accreditation Council for Graduate Medical Education.
