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N Engl J Med. 2019 Mar 7;380(10):905-914. doi: 10.1056/NEJMoa1810642.

Patient Safety Outcomes under Flexible and Standard Resident Duty-Hour Rules.

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From the Center for Outcomes Research, Children's Hospital of Philadelphia (J.H.S., O.E.-S., A.S.H., L.L.H., R.N.R.), the Departments of Pediatrics (J.H.S.), Anesthesiology and Critical Care (J.H.S.), and Medicine (L.M.B., J.A.S., K.G.V., D.A.A.), University of Pennsylvania School of Medicine, the Departments of Health Care Management (J.H.S., K.G.V., D.A.A.) and Statistics (D.S.S.), the Wharton School, the Leonard Davis Institute of Health Economics (J.H.S., J.A.S., D.S.S., K.G.V., D.A.A.), and the Department of Psychiatry (D.F.D., M.B.), University of Pennsylvania, and the Corporal Michael J. Crescenz Veterans Affairs Medical Center (K.G.V., D.A.A.) - all in Philadelphia; the Departments of Medicine (S.V.D.), Epidemiology (D.M.S., A.L.S., J.T.), and Biostatistics (J.T.), Johns Hopkins University, Baltimore; and the Department of Medicine, Brigham and Women's Hospital, Boston (J.T.K.).



Concern persists that extended shifts in medical residency programs may adversely affect patient safety.


We conducted a cluster-randomized noninferiority trial in 63 internal-medicine residency programs during the 2015-2016 academic year. Programs underwent randomization to a group with standard duty hours, as adopted by the Accreditation Council for Graduate Medical Education (ACGME) in July 2011, or to a group with more flexible duty-hour rules that did not specify limits on shift length or mandatory time off between shifts. The primary outcome for each program was the change in unadjusted 30-day mortality from the pretrial year to the trial year, as ascertained from Medicare claims. We hypothesized that the change in 30-day mortality in the flexible programs would not be worse than the change in the standard programs (difference-in-difference analysis) by more than 1 percentage point (noninferiority margin). Secondary outcomes were changes in five other patient safety measures and risk-adjusted outcomes for all measures.


The change in 30-day mortality (primary outcome) among the patients in the flexible programs (12.5% in the trial year vs. 12.6% in the pretrial year) was noninferior to that in the standard programs (12.2% in the trial year vs. 12.7% in the pretrial year). The test for noninferiority was significant (P = 0.03), with an estimate of the upper limit of the one-sided 95% confidence interval (0.93%) for a between-group difference in the change in mortality that was less than the prespecified noninferiority margin of 1 percentage point. Differences in changes between the flexible programs and the standard programs in the unadjusted rate of readmission at 7 days, patient safety indicators, and Medicare payments were also below 1 percentage point; the noninferiority criterion was not met for 30-day readmissions or prolonged length of hospital stay. Risk-adjusted measures generally showed similar findings.


Allowing program directors flexibility in adjusting duty-hour schedules for trainees did not adversely affect 30-day mortality or several other measured outcomes of patient safety. (Funded by the National Heart, Lung, and Blood Institute and Accreditation Council for Graduate Medical Education; iCOMPARE number, NCT02274818.).

[Available on 2019-09-07]
[Indexed for MEDLINE]

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