Flexible duty-hour programs for interns caused no more chronic sleep loss or sleepiness than standard program hours in a noninferiority trial published in the New England Journal of Medicine. However, noninferiority for alertness was not demonstrated for the flexible duty-hours group.
Sleep loss and work during night shifts reduce alertness and cognitive performance. Several changes have been made to intern and resident working hours, first in 2003, when the Accreditation Council for Graduate Medical Education limited resident workweeks to 80 hours and shifts to 30 hours, and then in 2011, when the council further limited shifts to 16 hours for interns. However, evidence has suggested that neither of these policy changes affected patient mortality, and in 2017, after publication of the FIRST trial, the 2011 changes were reversed.
Mathias Basner, MD, PhD, from the Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and colleagues randomly assigned 63 residency programs in the United States to follow either the standard 2011 duty-hour policies or flexible policies that kept the 80-hour workweek limit but put no limit on shift length or mandatory time off between shifts (iCOMPARE; ClinicalTrials.gov identifier: NCT02274818). The researchers compared sleep duration and morning sleepiness and alertness between the 2 groups. Outcome measures included actigraphy, the Karolinska Sleepiness Scale, and a brief computerized Psychomotor Vigilance Test.
The investigators acquired data during a 14-day period for 205 interns from 6 flexible programs and 193 interns from 6 standard programs. The average sleep time per 24 hours did not differ significantly between the 2 programs, at 6.85 hours for those in the flexible programs and 7.03 for those in the standard programs. Duration of sleep was noninferior among those in flexible programs compared with those in standard programs (P =.02 for noninferiority). Karolinska Sleepiness Scale scores in the flexible group also were noninferior compared with those in the standard programs (P <.001). However, Psychomotor Vigilance Test scores in the flexible group did not indicate noninferiority (P =.10).
Limitations of the study included the lack of generalizability to smaller internal medicine programs, as the programs included in the study were medium to large. However, the authors feel that it is unlikely that work schedules and sleep would differ significantly from the programs included in the study.
Nonetheless, the authors contend that the findings of the study suggest a role for fatigue management training in residency and confirm that acute sleep loss and circadian rhythm disturbances reduce the alertness of interns who work over extended overnight shifts.
Basner M, Asch DA, Shea JA, et al; iCOMPARE Research Group. Sleep and alertness in a duty-hour flexibility trial in internal medicine. N Engl J Med. 2019;380:915-923