The common practice of requiring physicians-in-training to work many double,
and even triple, shifts results in performance reductions equivalent to the
effects of drinking several ounces of alcohol, according to a new study led
by a University of Michigan sleep researcher published in the Journal of the
American Medical Association.
Depending on the type of medical or surgical care they decide to specialize
in, young doctors can spend anywhere from three to 12 years in training. The
first year -- the internship -- is considered the most intense.
Thirty-four Brown University Medical School pediatric residents completed
standardized tests following two different schedules: a month of 44-hour
work weeks in office-based clinics with no overnight duties; and a month of
90-hour work weeks, including day shifts in the hospital's wards or
intensive care units, plus overnight shifts once every four or five nights.
Vigilance, Attention
Following the month of longer hours, the doctors' vigilance, attention and
driving skills were found to be impaired. Their test responses were
equivalent to their performance after consuming three to four alcoholic
drinks following a month of lighter duties.
"This adds to the growing evidence that sleep deprivation among medical
residents significantly impairs their ability to perform, although it is
important to note that we did not assess performance on specific medical
tasks," says J. Todd Arnedt, PhD, a sleep psychologist who is a clinical
assistant professor of psychiatry and neurology at the U-M Medical School.
Arnedt works in the the U-M Sleep Disorders Center and the U-M Depression
Center Sleep & Chronophysiology Laboratory.
Three Hours Sleep
Sleep diaries and an automatic wrist-watch activity monitor verified that
the residents on heavy work shifts got significantly less sleep per night on
average than those with lighter schedules during the study period.
In the 24 hours leading up to the test days, residents on a light schedule
slept an average of 6 hours and 37 minutes, compared with about 3 hours for
the residents on a heavy schedule.
The residents were tested four times, in two separate sessions. Two of the
tests were completed after they had worked a month of light duty without
overnight shifts; the tests were given before and after they consumed three
to four alcoholic drinks.
In the second session, they were tested on the day after an overnight shift
that came at the end of a month of 90-hour work weeks. During this session,
they were tested before and after drinking a non-alcoholic placebo beverage.
Of primary interest were the tests conducted after they had drunk either the
alcohol or the placebo.
Performance, Effort
The researchers asked the residents to rate their performance and effort on
the tests. Ratings of impaired performance were higher following the month
of heavy work shifts compared to the light schedules.
Residents also rated their effort as higher after heavy work shifts compared
to the lighter shifts with alcohol.
In addition, the residents rated their levels of sleepiness. During the
heavy call month, they felt more tired than during the light-call month,
even after they had consumed alcohol on the light-call rotation.
They were not allowed to nap on the test day or to use caffeine after noon.
All of the tests were conducted at 3 pm.
Reducing Fatigue-Related Impairment
Most of the tests took place before new work-hour restrictions were imposed
by the Accreditation Council for Graduate Medical Education in 2003.
Residents now are subject to the following rules: an 80-hour weekly
work-hour limit; a 24-hour limit on continuous duty time; in-house call duty
no more than once every three nights; and one day in seven free from all
patient care and educational obligations. All requirements are averaged over
four weeks.
The new regulations are "a good initial step," Arnedt noted, "but the
solution to the problem is not likely as simple as well-intentioned policies
aimed at reducing work hours, which can themselves have negative
ramifications," he pointed out.
"Our study, like others before it, does raise concerns about the performance
of sleep deprived physicians-in-training and suggests that strategies aimed
at reducing fatigue-related impairments are likely necessary," Arnedt said.
Alcohol Comparison
Arnedt and his colleagues are the first to study medical residents using the
sleep deprivation and alcohol comparison model, which has been used in other
populations, including truck drivers. Both sleep deprivation and alcohol
consumption impair a person's reaction time, attention, judgment, control
and driving ability.
In a Harvard University study published earlier this year, the authors found
that interns were more likely to have an automobile crash or near-miss while
driving after an extended work shift.
Arnedt's team found that skills on a driving simulator deteriorated in
residents who were tested after an overnight shift in the hospital at the
end of a month of heavy night work. The findings from these studies suggest
that the personal safety of residents who drive home after working all night
may be at risk.
"We need to continue to find simple, practical and effective strategies that
hospitals and senior doctors can take to reduce sleep deprivation among
residents," says Arnedt.
Rita Jenkins is a health journalist for Daily News Central, an online
publication that delivers breaking news and reliable health information to
consumers, healthcare providers and industry professionals:
http://www.dailynewscentral.com
