Hospital and surgeon experience and patient health outcomes after coronary artery bypass graft surgery

The Hospital Readmissions Reduction Program imposes financial penalties on hospitals with excess readmission rates for various conditions, including coronary artery bypass graft (CABG) surgery. While prior research has focused mainly on hospital-specific factors and their impact on patient mortality, surgeon risk factors and patient outcomes, such as readmission risk, have received less attention. We study three drivers of CABG readmission risk—hospital and surgeon case volume, variation in surgeon volume, and surgeon familiarity with hospitals. Drawing on unique patient data sets of CABG surgeries spanning 3 years, we study the relationships between hospital and surgeon case volume, readmission risk, and postoperative length of stay (PLOS). We find evidence of an inverted U-shaped relationship between case volume and readmission risk and a U-shaped relationship with PLOS. Our results also indicate that surgeon volume variation moderates the relationship between surgeon volume and readmission risk, where readmission risk increases with greater variation in surgeon volume. We observe that the impact of surgeon experience on readmission risk at the focal hospital outweighs their experience at other hospitals. Our study has significant implications for hospital resource management as it highlights the role of surgeon and hospital experience in improving patient outcomes after CABG surgery.