Abstract 214: The Association of Surgeon Experience With Expected Mortality of Coronary Artery Bypass Graft Surgery in New York State

Purpose: Public reporting of surgical outcomes can promote quality improvement. However, this could also incentivize surgeons to avoid high-risk patients. Senior surgeons, with established referral networks, may select lower-risk cases than their junior colleagues. This study aimed to assess the relationship between surgeon experience and expected mortality rate of cases performed.

Methods: Publicly available data on coronary artery bypass graft (CABG) surgeries between 2011-2013 were obtained from the New York State Department of Health. The 30-day expected mortality rate (EMR) for each CABG was calculated from validated models. Additionally, we obtained data on each surgeon’s medical school gradation year and board certification status from Internet sources, such as Doximity. Surgeon experience was calculated by subtracting the medical school graduation year from 2011, the start of the study period. A multivariable linear regression model was used to estimate the association between EMR and surgeon experience, adjusting for case volume and board certification status.

Results: Between 2011-2013, there were 132 cardiac surgeons that performed CABG at 39 hospitals across New York State. The mean surgeon experience was 25.1 years (SD 9.1 years) and the overall mean EMR of CABG surgeries was 1.46% (SD 0.38%). The unadjusted analysis showed a 0.005% increase in EMR per additional year of surgeon experience. However, this was not statistically significant (p=0.25, 95% CI -0.0036 to 0.0013). Through the multivariable linear regression model, we did not find evidence of a significant association between operator experience and the EMR of cases performed (0.0040% per year, p=0.35, 95% CI -0.0044 to 0.012%). There was a significant association between the number of cases performed during the study period and the EMR, with an increase in EMR by 0.0005% per additional case performed (p=0.04, 95% CI 0.00004 to 0.001). There was no significant association between board certification status and EMR (p=0.10).

Conclusion: Despite public reporting of CABG outcomes, our findings suggest that more experienced surgeons may not be exhibiting risk-avoidant behavior. Future research could focus on supplementing publicly reported physician-level data with patient-level datasets to better understand the association between surgeon experience and expected mortality rate of cases performed.