Does More Rest Make for Safer Doctors?

To me, it's a no-brainer to suggest that sleep deprivation has an adverse impact on the mental acuity and manual dexterity of health professionals. Residents - young MDs taking post-graduate training in everything from family medicine to neurosurgery work long hours and are exposed more often to sleep deprivation than are attending physicians like me. A new study just published in CMAJ looks at the impact of shorter duty hours on resident well being and on-the-job performance.

The study took place in the intensive care units or ICUs at two teaching hospitals in Toronto. It looked at the performance of 47 residents working in the ICU. Over the course of their two-month rotation, on the nights that they were on call, the residents were randomly assigned overnight work schedules of 12, 16 or 24 hours. The residents were assessed at regular intervals throughout their overnight shift. Those who worked longer hours at night had more fatigue, headaches, eye pain, nausea, were more lightheaded, and had more palpitations and muscle aches than those who worked shorter hours.

But, the researchers also found that the residents who worked shorter shifts overnight did not feel less tired than those who worked longer hours. They also found that cutting back on hours at night had no impact on how sleepy the residents were during the day and during the night.

In addition, giving residents more hours of sleep did not improve patient safety. During their two-month rotations spent on the ICU ward, nearly a thousand patients were admitted for an average length of stay of just six days. Over all, the rate of harmful errors committed by the residents was low - and the number of adverse events or errors that could lead to harm to patients was virtually the same among the residents who worked twelve hour overnight shifts as it was in the residents who worked only twelve hours. Overall, the patient mortality rate was also low, and the chance of a patient dying didn't vary with the length of the overnight shift.

Here's the kicker: of eight preventable adverse effects that occurred during the study, seven occurred during the 12-hour night schedule. The researchers' conclusion: shorter resident schedules aren't safer and may actually be less safe for patients than longer schedules.

Why would shorter duty shifts for residents be less safe for patients? Other members of the ICU staff on duty thought that the residents who worked shorter hours made poorer quality clinical decisions than the ones who were up for twenty-four hours. The staff thought the residents on shorter hours learned fewer clinical and social details about their patients. In other words, less time on duty meant less time to get to know the patient.

There may be another reason why shorter hours don't improve patient safety: they increase the number of handovers in which the departing resident has to transfer care over to a colleague. In a commentary published along with the study (it's behind a paywall - sorry about that), the director of the residency program at McGill University - one of the first to shorten resident duty hours - suggests that incomplete handovers mean the doctor taking over doesn't get critical information about the patient & so makes more mistakes,

This study comes at a critical junction in the topic of doctor fatigue. Until this study and a few others like it, hospitals and residency programs have been in an apparent race to reduce the impact of sleep deprived doctors by reducing the hours that they work at night. But lately, I'm starting to see a backlash against the new rules - in part from attending physicians and surgeons who don't like giving residents more hours to sleep because doing so disrupts their operating room schedules - in some cases forcing them to postpone scheduled operations on patients because residents aren't around to assist. Some residents themselves don't like the new rules because fewer hours on call mean they aren't getting the clinical experience they get when they stayed up all night. There are also concerns that newly-minted who graduate with fewer hours and fewer cases under their belts aren't as qualified as their predecessors when they get into practice.

This study does not invalidate the hypothesis that sleep deprivation is bad for patient care. As one anesthesia resident told me, you'd have to be ignorant to think it's not a problem. I've seen residents in the middle of the night ask the same question to a patient over and over again because they're too sleep deprived to remember the answer. There are residents who nearly fall asleep while assisting at an operation. Still, I'm not surprised to find doctors resisting the call to get more sleep.

That said, in the culture of medicine, MDs tend to think they know best. As I discovered when White Coat, Black Art hosted a panel of experts on a show last fall, they don't like being told by outsiders that they need to get more sleep. With greater transparency in health care, you might expect that surgeons have an obligation to tell patients that they're sleep deprived. But last year, the American College of Surgeons told members that informing patients about being sleep deprived is purely optional. It's like they don't get it.

In my opinion, public pressure is the only way to get us to mend our ways and get some more rest. But be prepared for some serious sticker shock. The only way we'll have better rested doctors is to pay for replacements and more professionals like nurse practitioners and physician assistants who can provide continuity of care when the doctor goes to sleep.