Impact of duty hours restrictions on quality of care and clinical outcomes.

BACKGROUND: In July 2003, the Accreditation Council for Graduate Medical Education instituted residency duty-hours requirements in response to growing concerns regarding clinician fatigue and the incidence of medical errors. These changes, which limited maximum continuous hours worked and total hours per week, often resulted in increased discontinuity of care. The objective of this study was to assess the impact of the duty-hours restrictions on quality of care and outcomes of patients with acute coronary syndrome.

METHODS: We performed a retrospective analysis of 1003 consecutive patients with acute coronary syndrome admitted to the University of Michigan Hospital between July 2002 and June 2004. Patients were stratified by hospital admission during academic year 2002-2003 (pre-duty-hours changes, n=572) and academic year 2003-2004 (post-duty-hours changes, n=431). Main outcome measures included differences in adherence to quality indicators, length of stay, and in-hospital and 6-month adverse events.

RESULTS: Post-duty-hours changes, there was an increase in the usage of beta-blockers (85.8% vs 93.8%, P <.001), angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (65.7% vs 71.8%, P=.046), and statins (76.2% vs 84.0%, P=.002) at time of discharge. Length of stay decreased from 3.1 days to 2.8 days, P=.002. There was no difference in in-hospital mortality (4.2% vs 2.8%, P=.23). Six-month mortality (8.0% vs 3.8%, P=.007) and risk-adjusted 6-month mortality (odds ratio 0.53, 95% confidence interval, 0.28-0.99, P=.05) decreased after the duty-hours changes.

CONCLUSIONS: Implementation of the Accreditation Council for Graduate Medical Education residency duty-hours restrictions on an academic inpatient cardiology service was associated with improved quality of care and efficiency in patients admitted with acute coronary syndrome. In addition, improved efficiency did not adversely impact patient outcomes, including mortality.