Impact of ACGME Work-Hour Restrictions on the Outcomes of Coronary Artery Bypass Grafting in a Cohort of 600,000 Patients

Abstract

Since the resident physician 80-h/wk restriction was implemented on July 1, 2003, little has been learned about the impact of this reform on patient outcomes after coronary artery bypass grafting (CABG). Using the Nationwide Inpatient Sample database, we identified 614,177 patients who underwent isolated CABG from 1998 through 2007. Of the 374,947 patients who underwent CABG at a teaching hospital, 133,285 (36%) belonged to the post-reform group. Hierarchic logistic and multivariable regression models were used to assess the independent effect of the reform after adjusting for potential confounding factors. Outcomes assessed were operative morbidity and mortality, and length of stay. Outcomes of CABG patients at non-teaching hospitals were used to control for time bias. In teaching hospitals, after risk adjustment, the post-reform era was associated with lower mortality risk (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.56-0.63; P < 0.001) but greater operative morbidity (OR, 1.5; 95% CI, 1.43-1.58; P < 0.001). Although the implementation of work-hour reforms was correlated with shorter lengths of stay, there were fewer routine home discharges (OR, 0.73; 95% CI, 0.73-0.76; P < 0.001). Outcomes at non-teaching hospitals were similar, except that operative morbidity rates were lower during the post-reform era. The implementation of the resident work-hour reform in teaching hospitals did not affect mortality rates in CABG patients but was associated with increased morbidity. Further studies are neededto identify the reasons for the post-reform increase inpostoperative complications at teaching hospitals.