Importance: In 2003, the first phase of duty hour requirements for US residency programs recommended by the Accreditation Council for Graduate Medical Education (ACGME) was implemented. Evidence suggests that this first phase of duty hour requirements resulted in a modest improvement in resident well-being and patient safety. To build on these initial changes, the ACGME recommended a new set of duty hour requirements that took effect in July 2011.
Objective: To determine the effects of the 2011 duty hour reforms on first-year residents (interns) and their patients.
Design: As part of the Intern Health Study, we conducted a longitudinal cohort study comparing interns serving before (2009 and 2010) and interns serving after (2011) the implementation of the new duty hour requirements.
Setting: Fifty-one residency programs at 14 university and community-based GME institutions.
Participants: A total of 2323 medical interns.
Main outcome measures: Self-reported duty hours, hours of sleep, depressive symptoms, well-being, and medical errors at 3, 6, 9, and 12 months of the internship year.
Results: Fifty-eight percent of invited interns chose to participate in the study. Reported duty hours decreased from an average of 67.0 hours per week before the new rules to 64.3 hours per week after the new rules were instituted (P < .001). Despite the decrease in duty hours, there were no significant changes in hours slept (6.8 → 7.0; P = .17), depressive symptoms (5.8 → 5.7; P = .55) or well-being score (48.5 → 48.4; P = .86) reported by interns. With the new duty hour rules, the percentage of interns who reported concern about making a serious medical error increased from 19.9% to 23.3% (P = .007).
Conclusions and relevance: Although interns report working fewer hours under the new duty hour restrictions, this decrease has not been accompanied by an increase in hours of sleep or an improvement in depressive symptoms or well-being but has been accompanied by an unanticipated increase in self-reported medical errors.