The impact of resident duty hour reform on hospital readmission rates among Medicare beneficiaries

Abstract

Background: A key goal of resident duty hour reform by the Accreditation Council for Graduate Medical Education (ACGME) in 2003 was to improve patient outcomes.

Objective: To assess whether the reform led to a change in readmission rates.

Design: Observational study using multiple time series analysis with hospital discharge data from July 1, 2000 to June 30, 2005. Fixed effects logistic regression was used to examine the change in the odds of readmission in more versus less teaching-intensive hospitals before and after duty hour reform.

Participants: All unique Medicare patients (n = 8,282,802) admitted to acute-care nonfederal hospitals with principal diagnoses of acute myocardial infarction, congestive heart failure, gastrointestinal bleeding, or stroke (combined medical group), or a DRG classification of general, orthopedic, or vascular surgery (combined surgical group).

Main measures: Primary outcome was 30-day all-cause readmission. Secondary outcomes were (1) readmission or death within 30 days of discharge, and (2) readmission, death during the index admission, or death within 30 days of discharge.

Key results: For the combined medical group, there was no evidence of a change in readmission rates in more versus less teaching-intensive hospitals [OR = 0.99 (95% CI 0.94, 1.03) in post-reform year 1 and OR = 0.99 (95% CI 0.95, 1.04) in post-reform year 2]. There was also no evidence of relative changes in readmission rates for the combined surgical group: OR = 1.03 (95% CI 0.98, 1.08) for post-reform year 1 and OR = 1.02 (95% CI 0.98, 1.07) for post-reform year 2. Findings for the secondary outcomes combining readmission and death were similar.

Conclusions: Among Medicare beneficiaries, there were no changes in hospital readmission rates associated with resident duty hour reform.

Figure 1

Unadjusted trends in readmission rates by hospital teaching intensity. Note: The Accreditation Council for Graduate Medical Education duty hour regulations were implemented on July 1, 2003. Pre-reform year 3 included academic year 2000–2001 ( July 1, 2000–June 30, 2001); pre-reform year 2, academic year 2001–2002; pre-reform year 1, academic year 2002–2003; post-reform year 1, academic year 2003–2004; and post-reform year 2, academic year 2004–2005. Readmission rates in hospitals of different teaching intensity changed at different rates before the onset of the duty hour reform (by Wald chi-squared test; P = 0.005 for combined medical group and P = 0.001 for combined surgical group). Unadjusted readmission rates were highest in the major and very major teaching hospitals (P < 0.0001).

Figure 2

Estimated probability of readmission for an average patient in hospitals of different teaching intensity for combined medical and surgical groups. Note: Plots show the adjusted risk of readmission for a hypothetical patient at hospitals with RB ratios of 1 (very major teaching hospital) and 0 (nonteaching hospital), using mean values of all the covariates.