Protected sleep hours for medical residents can increase their sleep time overnight and even keep them more alert in the morning, according to a study in the Journal of the American Medical Association.

The research, conducted by a team led by Kevin G. Volpp, M.D., Ph.D., of the Philadelphia Veterans Affairs Medical Center and the University of Pennsylvania, set out to examine whether a protected sleep time of 5 hours is practical and successful in expanding the time that interns sleep when they have to work extended duty overnight shifts.

A report was previously published by the Institute of Medicine (IOM) describing what needs to be done to resident work hours and work schedules to improve the safety of patients.

In order to lower the chance of fatigue-related errors when residents are in the hospital for extended periods, the report suggests that they should have a protected sleep period of 5 hours when they work a shift that is 16 hours or more.

The background information of the report stated:

“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.”

The experts conducted two randomized controlled trials for the purpose of their research. One took place at the Philadelphia Veterans Affairs Medical Center and the other was at the Hospital of the University of Pennsylvania.

There were 106 senior medical students and interns, however, 3 were not arranged to have study rotations. Among the remaining 103 subjects, sixteen subjects worked at the university hospital, 44 worked at the VA center, and 43 worked at both of the places.

The team randomly assigned twelve 4-week blocks to either of the two following:

  • a standard intern schedule – prolonged duty overnight shifts of at least 30 hours, equal to 1,200 overnight intern shifts at each location
  • a protected sleep period – workers could sleep from 12:30 a.m. to 5:30 a.m. with handover of their phone for work, equal to 1,200 overnight shifts at each location

Their changes in physical activity were monitored by actigraphs worn on the participants’ wrists. They were also asked to keep track of their sleep using sleep diaries.

Results showed that subjects at the VA center who had protected sleep received more hours of sleep on average than those without protected sleep (2.86 vs. 1.98).

Subjects with protected sleep at the university hospital received 3.04 hours of sleep on average vs. 2.04 hours among those without protected sleep.

The scientists discovered that the medical residents with protected sleep had a reduced chance of having call nights with no sleep:

  • VA center: 5.8% vs. 18.6
  • University hospital: 5.9% vs. 14.2%

After measuring the participants’ tiredness on a sleepiness scale, they found that those in the protected sleep group felt less tired after on-call nights.

The researchers concluded:

“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.”

Written by Sarah Glynn