The impact of trainees' working hour regulations on outcome in CABG and valve surgery in the State of New York

Background and aim: In 2011, the Accreditation Council for Graduate Medical Education (ACGME) restricted the first-year residents' duty-hour to less than 16-hour shifts, decreased the maximum shift duration for senior residents, and increased minimum time off after on-call duties. Whether these changes may have impacted the outcomes in cardiac surgery remains unclear.

Methods: We performed a difference-in-difference analysis of the New York State Cardiac Surgery Reporting System data in 2004-2006 (before the duty-hour policies change) and 2014-2016 (after the change). We evaluated differences in 30-day risk-adjusted mortality rates (RAMR) in coronary artery bypass grafting (CABG) and valve surgeries, stratifying data by hospital type: teaching hospitals (TH) versus nonteaching hospitals (NTH). NTH served as the control not affected by the duty-hour policies.

Results: (1) The overall surgical volume for CABG surgery has decreased over time (37,645-24,991), while the volume for valve surgery remained similar (20,969-21,532); (2) TH had better short-term outcomes for CABG procedures during 2014-2016 (median RAMR: 1.01% vs. 1.55% in TH vs. NTH, respectively; p = .025) as well as for valve procedures during both 2004-2006 (5.16% vs. 7.49%, p = .020) and 2014-2016 (2.59% vs. 4.09%, p = .033); (3) at difference-in-difference analysis, trainees' duty-hour regulations were not associated with worsening short-term outcomes in both CABG (p = .296) and valve (p = .651) procedures performed in TH.

Conclusion: The introduction of the 2011 trainees' duty-hour regulations was not associated with worse short-term outcomes for CABG and valve surgery performed in the State of NY by TH.