A study to determine whether a protected sleep period of 5 hours is feasible and effective in increasing the time slept by interns on extended duty overnight shifts was conducted by Kevin G. Volpp, M.D., Ph.D., of the Philadelphia Veterans Affairs Medical Center and University of Pennsylvania, Philadelphia.
In 2009, the Institute of Medicine (IOM) published a report on resident work hours and work schedules to improve patient safety that recommended a protected sleep period of 5 hours during any work shift longer than 16 hours to reduce the risk of fatigue-related errors when residents are in the hospital for prolonged duty periods of up to 30 hours. "The IOM report acknowledged that there was a paucity of data on optimizing duty hours for physicians in training but argued that the evidence on the hazards of fatigue-related performance errors in other professions likely extended to medicine," according to background information in the article.
For the study, two randomized controlled trials were conducted in parallel: one at the Philadelphia Veterans Affairs Medical Center, the other at the Hospital of the University of Pennsylvania (2009-2010). Of the 106 interns and senior medical students who consented, 3 were not scheduled on any study rotations. Among the others, 44 worked at the VA center, 16 at the university hospital, and 43 at both. Twelve 4-week blocks were randomly assigned to either a standard intern schedule (extended duty overnight shifts of up to 30 hours; equivalent to 1,200 overnight intern shifts at each site), or a protected sleep period (protected time from 12:30 a.m. to 5:30 a.m. with handover of work cell phone; equivalent to 1,200 overnight intern shifts at each site). Participants were asked to wear wrist actigraphs (monitors changes in physical activity) and complete sleep diaries.
The researchers found that at the VA center, participants with protected sleep had an average 2.86 hours of sleep vs. 1.98 hours among those who did not have protected hours of sleep. At the university hospital, participants with protected sleep had an average 3.04 hours of sleep compared to 2.04 hours among those who did not have protected sleep. Participants with protected sleep were significantly less likely to have call nights with no sleep: 5.8 percent vs. 18.6 percent at the VA center and 5.9 percent vs. 14.2 percent at the university hospital. As gauged by a sleepiness scale, participants felt less sleepy after on-call nights in the intervention group.
"Although there is evidence that obtaining sleep (relative to no sleep) during prolonged duty helps reduce fatigue and that the amount of fatigue reduction increases with the amount of sleep, from this study we do not have evidence that this is also associated with improvements in patient outcomes. A rigorous comparative effectiveness analysis of protected sleep times vs. 16-hour shifts in improving intern alertness and cognitive function and patient outcomes could have a significant effect on policy. To the extent that protected sleep periods are feasible and improve alertness, they may provide a reasonable alternative to mandated shorter shifts," the authors conclude.