Problem definition: In many service systems, individual server’s workload can have a substantial impact on service time and quality. Such effects are particularly important in healthcare systems which often operate under resource and time constraints. In much of the literature, this has been primarily considered at the system level rather than the individual level. In this study, we investigate this relationship in the context of cardiac surgery, i.e., how surgery duration and patient outcomes are affected by individual surgeon’s daily workload.
Methodology/results: Using a detailed data set of more than 5,600 cardiac operations in a large hospital, we quantify how individual surgeon’s daily workload (e.g., the number of operations performed by the focal surgeon) affects surgery duration and patient outcomes. To handle the endogeneity of surgeon daily workload, we construct instrumental variables using the cardiac department’s operational factors, including the block schedule of surgeons. We find that high daily workload for the focal surgeon is associated with longer incision times and worse patient outcomes. Specifically, the surgeon’s higher daily workload leads to longer post-surgery length-of-stay in the ICU and hospital as well as higher likelihoods of reoperation and readmission for their patients. These results highlight the potential negative impact of high individual surgeon workload which may result in surgeon fatigue and operational constraints. We then develop a surgical scheduling model that incorporates the estimated impact of surgeon workload. We solve the model by mixed-integer quadratic programming and show that our proposed schedule can substantially reduce total incision time and post-surgery length-of-stay.