(Reuters Health) - Hospital residents working 80 hours a week get nearly as much sleep and provide comparable patient care whether their schedule is highly-structured or more flexible, according to a study looking at two types of extended shifts.

The rates of death within 30 days for patients treated by the residents were 12.2 percent in training programs where shifts were limited to 16 hours a day, five days a week, and 12.5 percent where the 16-hour limit could be exceeded and could be as long as 28 hours or more.

“We found no increase in safety concerns with flexible shifts compared to the shift structures that were much more restrictive,” Dr. David Asch, principal investigator of the iCOMPARE study, told Reuters Health in a telephone interview.

When investigators looked at average sleeping time among interns, both schedules gave the doctors-in-training roughly the same number of hours of sleep through the week.

However, in a measure of alertness using a smartphone test, the physicians on regular schedules proved to be sharper.

“We can confidently say that working flexible hours, still within the 80-hour constraints, does not result in higher patient mortality than working standard hours. We also now know that interns do not sleep significantly more or less when following either of these schedules,” Drs. Lisa Rosenbaum and Daniela Lamas of Brigham and Women’s Hospital in Boston conclude in an editorial accompanying the two studies in the New England Journal of Medicine.

But Dr. Charles Czeisler, director of the division of sleep and circadian disorders at Brigham and Women’s Hospital in Boston, who was not involved in the research, said the iCOMPARE results do not prove that it is safe to sleep-deprive doctors.

The study measured physician performance under work schedules where everyone was at risk for sleep deprivation, he said, especially since 3 out of 4 of the resident physicians they studied were exempt from important rules adopted to protect doctors and patients.

Neither the flexible group nor the control group gave residents and interns close to the amount of protected sleep time recommended by a landmark 2009 analysis by the Institute of Medicine, Czeisler said in a phone interview.

“It’s equivalent to studying the dangers of smoking but letting everyone smoke,” he said. “You don’t have a non-fatigued group here. They were both exhausted groups.”

Concern about the extraordinarily long work hours that residents and interns are required to work, and how they affect the quality of care, prompted new rules in 2011 limiting shift duration.

But some have argued that it would be better to give the doctors-in-training longer shifts to provide more continuity of care.

The results of the study are tempered by the fact that flexible programs in the trial were permitted but not required to use extended shifts, the researchers note.

If the quality of care was comparable in the two groups, Czeisler argued, it’s better to use the system where doctors-in-training are allowed to get adequate rest “because of the risk to the resident physicians themselves in terms of their physical health, their mental health, and the risk of sleep-deprived residents having a car crash or occupational injury.”

When sleep patterns of the interns were measured using wrist monitors, average sleep time was 6.85 hours per day for people in the flexible program versus 7.03 hours with the standard hours.

But there were big differences depending on the type of shift the intern was on; the biggest discrepancy in sleep came after Day 2 of an extended overnight shift, when interns in the flexible group typically got 5.12 hours versus 7.35 hours on the more regimented schedule.

“The reality is healthcare is a 24/7 business. Humans can’t operate 24/7. So, the trick is to figure out approaches to manage the needs of humans who need a natural sleep cycle,” said Asch, a professor of medicine at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. “What matters is how we anticipate and respond to natural fatigue, with redundant supervision, with sleeping when possible.”

SOURCE: bit.ly/2GZbwts, bit.ly/2EHrGFw and bit.ly/2C1M0jd The New England Journal of Medicine, online March 6, 2019.