Volume-Outcome Relationship in Cardiac Surgery

Natalya Vinokurova, Management, The Wharton School

Abstract: In this project, I am continuing to use the empirical context of the evolution of cardiac surgery regulation in New York State to understand the challenges involved using empirically-documented social science findings into public policy. Specifically, I am looking to understand how the doctors asked to evaluate their colleagues’ performance use a combination of personal judgment and academic research to shape the regulation of cardiac surgery. This funding request will help me complete the project for which I received the funds over the past four years. The grants from the Mack Institute to-date enabled me to staff-up my RA team that is working on helping me clean the data I have collected for this project. The team of 3 undergraduate RAs has finished summarizing the individual documents in the dataset. My goal for this summer is to complete the data analysis on this project.

Background: This project focuses on understanding the experience of New York State with tracking risk-adjusted outcome data for coronary surgery and the uses of this data for policy-making. In 1989, New York State mandated the reporting of risk-adjusted data on open heart surgeries performed in the state. Between 1989 and 1991, the risk-adjusted mortality rate for Cardiac Artery Bypass Graft (CABG) surgery fell by more than 40% as the state moved aggressively to restructure and shut down low-volume programs.

NJ and PA, the states that replicated New York’s data collection experiment exactly have witnessed similar drops in risk-adjusted mortality. The results have been less dramatic for Massachusetts and California, the states that only implemented parts of the New York protocol. The remaining 44 states are yet to follow New York’s example.

This study uses a combination of historical and ethnographic methods to answer the following three questions. Why did it take New York State almost 20 years from understanding the relationship between volume and outcomes to instituting the data collection? What combination of institutional factors enabled New York State to institute the collection of risk-adjusted data? And, finally, what prevented other states from copying New York’s model?