An unintended, and potentially harmful, consequence of the 16-hour shift limit for first-year residents is an increase in self-reported medical errors, according to a study published online March 25 in JAMA Internal Medicine. In contrast to the patient safety issue, the requirement had nonsignificant impacts on hours slept, depressive symptoms and well-being scores.
In July 2011, the Accreditation Council for Graduate Medical Education (ACGME) established a new set of duty hour recommendations, including limiting shift length for interns from 30 hours to 16 hours. Previous research focused on shorter shifts in the intensive care unit had suggested that reduced hours could cut the incidence of serious medical errors. However, other data have linked limited shift length with more patient handoffs and a higher rate of errors.
Srijan Sen, MD, PhD, from the department of psychiatry at the University of Michigan, Ann Arbor, and colleagues sought to evaluate the effects of the recommendation on interns and their patients.
The researchers conducted a longitudinal cohort study comparing interns serving in 2009 and 2010 with interns serving after 2011. They sent a survey assessing general demographic factors and psychological factors to 51 residency programs two months prior to internship and 2,323 interns responded. Interns also completed a survey focused on work hours, sleep and medical errors at months 3, 6, 9 and 12 of the internship year. Depressive symptoms were assessed via the Patient Health Questionnaire (PHQ).
The mean number of duty hours per week decreased significantly across the four assessments, from 67 to 64.3. However, the mean number of hours slept each day held steady for both cohorts, at 6.8 hours for the preimplementation cohort and 7 for the postimplementation cohort. The finding indicates it may be necessary to design work schedules that accommodate for circadian phase and to train residents on practices to increase sleep time and improve sleep quality, according to Sen et al.
Interns who reported a concern about making a serious medical error rose significantly from 19.9 percent to 23.3 percent, the researchers found. "That's a 15 to 20 percent increase in errors—a pretty dramatic uptick, especially when you consider that part of the reason these work-hour rules were put into place was to reduce errors," Sen said in a release. This may be linked to the increased number of patient handoffs prompted by the ACGME reforms.
Depressive scores also were unaffected at 5.8 preimplementation and 5.7 postimplementation.
The researchers referred to previous studies which had reported a substantial increase in depressive symptoms during internship. Higher levels of depression have been linked to more medical errors and poorer clinical performance. “In this sample, we found further evidence supporting this link, with interns meeting PHQ criteria for depression reporting medical errors (35.3 percent) at almost twice the rate as nondepressed interns (17.8 percent).”
Another unforeseen consequence of the duty-hour change may have been the exacerbation of work compression, “with residents expected to complete the same amount of work as previous cohorts but in less total time.”
The new data don't definitively support any one of these theories as the culprit in the rise in error rates or the lack of progress in sleep hours and well-being among young doctors, Sen cautioned in the release. Further study is needed to assess the issue and determine how to better support young physicians and maintain or improve patient safety, he concluded.