It's not enough just to reduce residents' hours

On the surface, two of the most recent studies looking at the new resident work hour rules in the context of patient safety would seem to be contradictory.

A literature review of studies evaluating the impact of sleep on patient safety, published in the Dec. 7, 2004, Annals of Internal Medicine, found that having residents work fewer hours didn't affect patient mortality.

In contrast, research by the Harvard Work Hours, Health and Safety Study was hailed this fall as the most rigorous proof to date that fatigue is in fact a primary factor behind medical errors.

Kathlyn E. Fletcher, MD, assistant professor of internal medicine at the Medical College of Wisconsin and a clinician-researcher at the VA Medical Center, Milwaukee, led the literature review.

More sleep, safer patients?

Dr. Fletcher said the apparent contradictions between her work and the landmark Harvard study are more a reflection of the complexity of the issue than of conflicting findings.

"There's been a general perception that by decreasing work hours, by definition we'll be improving patient safety," she said. "This review shows that can happen, but it doesn't always happen. You must do it in a manner that still provides excellent patient care."

The review found seven intervention studies from 1990 to March 2004 that assessed patient safety outcomes in relation to changes made to counteract long work hours, fatigue or sleep deprivation.

Because the Harvard work was published in the Oct. 28, 2004, issue of the New England Journal of Medicine, it was not available when the literature review was conducted. In one study, mortality was unchanged as residents' hours were reduced; in another, patients were more likely to have a complication or test delay when residents' hours were cut.

Dr. Fletcher said the way scheduling changes are implemented makes a big difference in whether patient safety improves as a result. The program in the Harvard study was able to add an intern to make the new schedule work.

"They demonstrated that by decreasing hours and adding an extra person, there were fewer errors," she said. "Our review shows that you don't always reduce errors by just reducing hours."

She said the effort to reform residents' hours is the right idea, but not all programs will be as effective in implementing these reforms as the one in the Harvard study.

"I don't want to be an alarmist, but I want programs to follow up and make sure the interventions they put into place to reduce hours still maintain safety and don't actually put people at risk," Dr. Fletcher said.

David F. Dinges, PhD, professor of psychology at the University of Pennsylvania School of Medicine, said there were a host of factors that might increase medical risks, which could explain the disparate results shown in the research.

"I think it's fine if there's some controversy over the evidence and what to do about it," said Dr. Dinges, who is also chief of the school's division of sleep and chronobiology and director of its unit for experimental psychiatry. "Everybody assumes that the hours the [Accreditation Council for Graduate Medical Education] imposed will take care of the matter, but this is just the beginning," he said.

While Dr. Fletcher's literature review documents a variety of patient safety results, Dr. Dinges said the Harvard study provides the highest caliber information on the subject so far. Even so, more research is needed to capture a better picture of the impact of the revised resident hours, he said.

Given the demands on physicians, particularly those not constrained by ACGME hour limits, getting more sleep may not be an option.

"If you can't solve the acute throughput -- the sheer volume of patients coming through the hospital -- we'll have errors," Dr. Dinges said. "... If we want all those hours of patient care and have a limited number of people giving them, then we need to find a way to use technology to prevent errors."