IMPORTANCE

Patient outcomes associated with the 2011 Accreditation Council for Graduate Medical Education (ACGME) duty hour reforms have not been evaluated at a national level.

OBJECTIVE

To evaluate the association of the 2011 ACGME duty hour reforms with mortality and readmissions.

DESIGN, SETTING, AND PARTICIPANTS: Observational study of Medicare patient admissions (6,384,273 admissions from 2,790,356 patients) to short-term, acute care, nonfederal hospitals (n = 3104) with principal medical diagnoses of acute myocardial infarction, stroke, gastrointestinal bleeding, or congestive heart failure or a Diagnosis Related Group classification of general, orthopedic, or vascular surgery. Of the hospitals, 96 (3.1%) were very major teaching, 138 (4.4%) major teaching, 442 (14.2%) minor teaching, 443 (14.3%) very minor teaching, and 1985 (64.0%) nonteaching.

EXPOSURE

Resident-to-bed ratio as a continuous measure of hospital teaching intensity.

MAIN OUTCOMES AND MEASURES

Change in 30-day all-location mortality and 30-day all-cause readmission, comparing patients in more intensive relative to less intensive teaching hospitals before (July 1, 2009-June 30, 2011) and after (July 1, 2011-June 30, 2012) duty hour reforms, adjusting for patient comorbidities, time trends, and hospital site.

RESULTS

In the 2 years before duty hour reforms, there were 4,325,854 admissions with 288,422 deaths and 602,380 readmissions. In the first year after the reforms, accounting for teaching hospital intensity, there were 2,058,419 admissions with 133,547 deaths and 272,938 readmissions. There were no significant postreform differences in mortality accounting for teaching hospital intensity for combined medical conditions (odds ratio [OR], 1.00; 95% CI, 0.96-1.03), combined surgical categories (OR, 0.99; 95% CI, 0.94-1.04), or any of the individual medical conditions or surgical categories. There were no significant postreform differences in readmissions for combined medical conditions (OR, 1.00; 95% CI, 0.97-1.02) or combined surgical categories (OR, 1.00; 95% CI, 0.98-1.03). For the medical condition of stroke, there were higher odds of readmissions in the postreform period (OR, 1.06; 95% CI, 1.001-1.13). However, this finding was not supported by sensitivity analyses and there were no significant postreform differences for readmissions for any other individual medical condition or surgical category.

CONCLUSIONS AND RELEVANCE

Among Medicare beneficiaries, there were no significant differences in the change in 30-day mortality rates or 30-day all-cause readmission rates for those hospitalized in more intensive relative to less intensive teaching hospitals in the year after implementation of the 2011 ACGME duty hour reforms compared with those hospitalized in the 2 years before implementation.