In findings published in this week's issue of the Journal of the American Medical Association, 34 young pediatric residents showed similar impairments in vigilance, attention, and driving skills on standardized tests after they had been on duty overnight in the hospital and worked a month of 90-hour weeks, compared with when they had consumed three to four alcoholic drinks after a month of 44-hour weeks with no overnight duties.
The study involved medical residents from Brown University Medical School and was led by a sleep researcher from the University of Michigan Health System. Most subjects were tested before new national requirements limited resident work hours to an average 80-hour work week and maximum 24-hour work day.
The team monitored participants' sleep habits during the study using sleep diaries and an automatic wrist-watch activity monitor, which verified that the residents on heavy work shifts got significantly less sleep per night on average than those with lighter schedules.
They also 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 work shifts and residents rated their effort as higher after heavy work shifts compared to the light work shifts with alcohol.
"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, Ph.D. a sleep psychologist who is a Clinical Assistant Professor of Psychiatry and Neurology at the U-M Medical School.