Interns continue to work overly long shifts, study finds

That intern working on you at the hospital may be so sleep-deprived his or her performance is no better than that of a drunk. That’s one conclusion of a national study by investigators at the Harvard Medical School.

Earlier surveys of a variety of medical centers found that sleepy doctors-in-training endanger both patients and themselves. To cut off federal attempts to solve this serious problem by legislation, the Accreditation Council for Graduate Medical Education, in 2003, put a cap on hours that residents and interns training to be medical doctors can work. (Interns are those in their first year of training.) The rules limited shifts to a maximum of 30 consecutive hours and no more than 80 hours a week. In addition, residents and interns must have one day off in every seven.

Researchers at the Harvard Medical School and Brigham and Women’s Hospital in Boston did a nationwide study of interns’ working hours before and after the new rules and found that interns still put in dangerously long shifts, despite the accreditation council’s claims to the contrary.

The council “developed the duty-hour standards out of concern for the effects of excessive resident work-hours on patient and resident safety,” notes Christopher Landrigan, an assistant professor at Harvard Medical School. “Staying awake for 24 consecutive hours induces decrements in human performance similar to a blood alcohol level of 0.1 percent.” That’s high enough to get you arrested for drunk driving in most states.

Referring to a 2004 Harvard report on sleep-deprived interns, Charles Czeisler, Baldino Professor of Sleep Medicine, says, “Interns made 36 percent more serious medical errors during a traditional work schedule than during a schedule that eliminated marathon 24-hour work shifts.”

Long hours can be as hard on the interns as on their patients. In a study published last year, Czeisler and colleagues found that “the odds interns will have a documented motor vehicle crash on their commute after an extended work shift were more than double those after a nonextended shift.”

Long shifts persist

These are the kinds of mistakes and accidents the accreditation council’s standards were intended to prevent. And it claims success, reporting that only 5 percent of residency training programs in the United States did not comply with the reduced work hours. However, in the Harvard study, almost 84 percent of 1,278 interns reported work hours that violated maximum allowed limits during one or more months in the year after the rules were introduced.

More than two-thirds of them (67.4 percent) reported working shifts longer than 30 consecutive hours. In the months from July 2003 to May 2004, nearly half (43.7 percent) did not get the mandated one day in seven off from work. Forty-three percent worked more than 80 hours a week. Twelve percent of their work weeks exceeded 90 hours. Four percent exceeded 100 hours.

The new rules didn’t add up to much less work or more sleep. Work decreased only from a mean of 71 to 67 hours a week. Sleep increased an unimpressive 22 minutes a night.

Why the big discrepancy between the council’s survey and the Harvard study? “Most of the difference in our results is likely explained by differences in survey methodology,” says Landrigan, a sleep medicine and patient safety specialist at Harvard-affiliated Brigham and Women’s and Children’s hospitals. Harvard researchers asked more open-ended questions compared with the accreditation council. In their report, published in the Sept. 6 issue of the Journal of the American Medical Association, Landrigan and colleagues claim that the council’s questions’ “may have limited the accuracy of responses” and “altered reporting.”

Then there’s the conflict-of-interest problem. Reports of violations of council standards “could lead to a loss of program accreditation,” Landrigan points out. Therefore, such disclosures “could threaten residents’ own careers,” he says.

Harvard investigators rigorously checked their results by matching reported hours in the survey with those in diaries kept by the interns. A sample of diaries was further checked by directly observing work hours. And the quality and amount of sleep was monitored by brain wave recordings of 20 interns.

Errors decrease with hours

How come ignoring rules that help both patients and residents is so common? The Harvard report notes that the new standards were not backed up by financial and technical support. Training hospitals “may not have the resources or expertise to redesign their schedules to the extent required,” Landrigan notes. In addition, residents “are typically unwilling to depart immediately at a change of shift when a patient care situation demands their continued presence. Such situations are common in high-intensity settings, yet most scheduling systems do not account for these commonplace emergencies.”

Another block to noncompliance, is the “if I did it, they can do it” attitude of senior doctors. “There exists a widespread perception among many physicians that fatigue is not a problem despite the accumulation of considerable evidence to the contrary,” notes the Harvard report.

That evidence includes studies done at Brigham and Women’s Hospital. Interns who were on duty an average of 85 hours a week, including two shifts lasting 24-30 hours, had their workweek reduced to 65 hours. Their continuous shifts were cut to 16 hours, and they enjoyed about six more hours of sleep a week.

Though most of us would think of 65-hour weeks and 16-hour shifts as exhausting, those working these reduced shifts made significantly fewer serious medical errors than those working traditional schedules. For example, serious diagnostic mistakes fell 80 percent.

In Europe, laws limit physicians’ shifts to 13 consecutive hours and 48 to 58 hours a week.

“The bottom line is that the current system in this country is unsafe,” Landrigan says. “Our regulations still allow shifts that are too long according to the safety standards of any other industry in the United States and for physicians in other countries.” As a fix, he wants to see new regulations established based on accumulated evidence that such long hours endanger the health and safety of both doctors and patients. And once such regulations are in place, “hospitals need mechanisms and resources to enforce limits on the number of consecutive hours,” he comments.

In the meantime, should patients in hospital wards ask a bleary-eyed doctor how long he or she has been awake? “Those kinds of questions are well within the right of patients to ask,” Landrigan agrees. “Frankly, I think it could be beneficial to do so.”

However, that doesn’t solve the problem. “If it’s 3 a.m., the answer typically will be 20-22 hours,” Landrigan says. “But there may not be anyone else available who has worked fewer hours. Until that changes, I think patients are pretty much out of luck.”