Strengths and Limitations
The strengths of our study include the use of two high-volume statewide databases, which capture a very large number of surgeons relative to many other studies that have investigated this relationship. Additionally, our dataset is comprised of two mandatory statewide outcome reporting systems, which minimize potential selection bias or a narrow scope of payer-specific databases such as Medicare data. A limitation of our dataset is that while EMR is a strong measure of high vs low risk patients, it does not necessarily reflect information about case complexity or whether a case is elective vs nonelective, which will be an important area for future investigation. Differences in the California and New York risk models is another limitation of our dataset – though these differences should be adequately adjusted for by normalizing EMR by respective state mortality averages.