Shorter hours for interns can increase patient handoff risk

Johns Hopkins researchers say they have uncovered an unintended consequence of the move in recent years to reduce the legendarily long and onerous work hours of interns. Shorter work hours can increase the risks of patient handoff, they say.

Limiting the number of continuous hours worked by medical trainees also failed to increase the amount of sleep each intern received per week, but it dramatically increased the number of potentially dangerous handoffs of patients from one trainee to another, the research from Johns Hopkins suggests. The reductions in work hours also decreased training time, the researchers found. (The study is available online at

In 2011, stricter national regulations, reducing the continuous-duty hours of first-year resident physicians from 30 to 16, were put in place with the theory that limiting trainees’ work hours would lead them to sleep more and that less fatigue would translate to fewer serious medical errors. But lead researcher Sanjay V. Desai, MD, an assistant professor of medicine at the Johns Hopkins University School of Medicine and director of the internal medicine residency program at The Johns Hopkins Hospital in Baltimore, MD, says data from his work do not support that idea. Instead, he says, his research suggests that unintended consequences of the new rules could be making patients less safe and compromising resident training.

“The consequences of these sweeping regulations are potentially very serious,” Desai says. “Despite the best of intentions, the reduced work hours are handcuffing training programs, and benefits to patient safety and trainee well-being have not been systematically demonstrated.”

He says the 16-hour limit was put in place without evidence of whether it would improve patient safety and outcomes. “We need a rigorous study,” Desai says. “We need data to inform this critical issue.”

Desai and his Johns Hopkins colleagues compared three work schedules in the months leading up to the 2011 change. For three months, groups of medical interns were assigned randomly to a 2003-compliant model of being on call every fourth night, with a 30-hour duty limit, or to one of two 2011-compliant models. The latter included being on call every fifth night but working only 16 hours straight, or a night float schedule, which essentially had interns working a regular week on the night shift not exceeding 16 hours.

Although interns on the 16-hour limit schedule did sleep an average of three hours longer during the 48 hours encompassing their on-call period than those working 30-hour shifts, there was no difference in the amount of sleep they received across a week. “During each call period, the interns had 14 extra hours out of the hospital, but they only used three of those hours for sleeping,” Desai says. “We don’t know if that’s enough of a physiologically meaningful increase in sleep to improve patient safety.”

In the study, the researchers found, the minimal number of patient handoffs between interns increased from three for those working 30 hours to as high as nine for those working 16-hour shifts. When handoffs increase, there is less continuity of care and more room for medication and other treatment and communication errors, past research has shown.

Meanwhile, the minimal number of interns caring for a given patient during a three-day stay increased from three to as high as five. Whether, or in what way, that number affects patient care or patient satisfaction is another unknown, Desai says.