Obtaining this extremely large sample size from a practical setting allows researchers to better understand processes such as the relationship between surgeons’ volume and outcomes. In turn, this analysis provides hospitals, patients, and surgeons with customer review a quantifiable measure of the benefits of surgeons’ volume on outcomes in lung surgery. The sample size and large number of elements in the Premier database allows for analyzing the effect of experience with VATS on inpatient costs, length of surgery, length of stay, as well as the likelihood and number of adverse surgical events. In this retrospective analysis, we find evidence of volume-outcome relationship. The relationship is stronger (1) for cost and utilization outcomes as opposed to adverse events, (2) for thoracic surgeons rather than other surgeons, and (3) for VATS lobectomy procedures more than for VATS wedge resection procedures.

Finally, we find that while there was a reduction in cost and resource utilization associated with greater experience with VATS, these outcomes were not strongly linked with greater experience with open procedures. Thus, by and large, performance with VATS is associated primarily with experience with VATS. The choice between VATS and open lobectomy has implications for the surgeon’s learning profile, as the reduction in cost and resource utilization associated with greater experience with VATS were much larger than those associated with greater experience with open procedures. This finding reinforces the need for surgeons’ specialization and centralization of delivery for VATS.

There were certain limitations of this study. This is a retrospective analysis from a transactional database (Premier) and not a prospective analysis where randomization and more detailed information about patients and procedures could be collected. For instance, it would have been of interest to examine the influence of additional patient characteristics, such as weight or BMI, and more procedure-related details. Nevertheless, we include numerous controls in our analysis, particularly, controls for patient characteristics [30] and hospital characteristics [12]. Another limitation, and a topic that can be the focus of future research, is the lack of information on surgeons’ characteristics. In particular, data associated with surgeons’ characteristics (e.g., years in practice, graduate of which medical school, completion of fellowship, etc.) would be of interest. This information may be important as surgeons do not randomly adopt Drug_discovery VATS, and the results may therefore be biased if the most able surgeons are also the ones who adopt and utilize VATS extensively. 5.