Distributed May 3, 2003
For Immediate Release

News Service Contact: Scott Turner

Sleep loss and driving do not mix for medical residents, study finds

In a driving simulation, fatigued pediatric residents performed equally or worse than they did when moderately intoxicated, according to a pilot study presented at the 2003 Pediatric Academic Societies’ meeting by Brown Medical School researchers.

SEATTLE, Wash. — Medical residents who drive home after a month-long rotation of on-call duty may be a threat behind the wheel. In a driving simulation, fatigued residents performed equally or worse than when they were moderately intoxicated, according to a pilot study presented at the 2003 Pediatric Academic Societies’ meeting.

This is the first study to compare resident fatigue to an accepted standard of functional impairment: moderate alcohol intoxication (blood alcohol concentration of 0.04 percent to 0.06 percent).

“Sleep loss and its consequences are an occupational hazard in medicine,” said study co-leaders Judith Owens, M.D., associate professor of pediatrics, and J. Todd Arnedt, assistant professor of psychiatry and human behavior. “Federal work-hour changes to address fatigue among medical residents were necessary, but they are not sufficient to ensure that residents are well rested.”

Residency programs must do a better job “of educating residents about sleep deprivation, the consequences for driving home safely, and about countermeasures that mitigate the effects of fatigue,” Owens said. “I don't think this is discussed in residency programs. Medical education programs don't talk about it, either.” Planned naps and calculated use of caffeine are two of several strategies that may temporarily offset the effects of sleep loss, she said.

Most medical rotations last about a month. Even with the new work-hour guidelines in place as of July 1, 2003, a heavy on-call schedule can entail up to four consecutive 80-hour weeks. The authors suggest that training programs consider residents’ level of alertness and their abilities to drive home after being on call.

“Creative solutions on the part of residency programs, such as providing a place for a resident to nap or to having a taxi service available to drive a sleepy resident home post-call, are key,” Owens said. “Programs can also stress to residents that they get adequate sleep when not on call.”

Researchers tested and compared simulated driving performance and the ability to judge one’s own impairment among 15 pediatric residents under four situations: rested, sleep-deprived, rested but moderately intoxicated, and sleep-deprived plus placebo.

It took just 15 study participants to produce a statistically significant effect from sleep loss. When fatigued, residents had particular difficulty performing the driving task successfully. Their abilities to maintain lane position and constant speed were worse compared to placebo and as impaired or worse compared to being moderately intoxicated.

On a positive note, said Owens, fatigued residents predicted their level of performance on the driving simulator more accurately than when they were intoxicated. “It's encouraging that they recognized their own diminished skills, because in general people are not good at self-judging sleepiness and impairment related to fatigue,” she said. “It only takes three to four seconds to fall asleep into a drowsy driving crash.”

The study was designed to reflect “what residents were exposed to in the course of their occupational duties,” said Owens. “But this is preliminary data and the study was performed on a driving simulator, which does not necessarily predict how well tired residents will perform in real world conditions. Still the findings have significant implications for resident safety.”

The Sleep Medicine Education and Research Fund of the American Academy of Sleep Medicine (AASM) supported the study. Owens chairs an AASM task force called SAFER, which stands for Sleep Alertness and Fatigue Education in Residency. Recently, the task force developed an evidence-based, educational package for residents, which addresses facts, myths and misconceptions about fatigue. Those materials become available to residency programs nationwide July 1.

Other researchers in the study included Mary A Carskadon, professor of psychiatry and human behavior, and research assistants Jessica Stahl and Megan Crouch.