Thyroid and parathyroid surgeon case volume influences patient outcomes: A systematic review

Background: The study aim was to systematically review literature evaluating surgeon volume-outcome relationships for thyroid and parathyroid operations in order to inform surgical quality improvement initiatives. Current literature suggests surgeons who perform a high volume of thyroid and/or parathyroid operations have better outcomes than low volume surgeons, though specific volume definition are not standardized. Methods: Eligible studies were selected through a literature search focused on the effect of surgeon volume on thyroid and parathyroid surgery patient outcomes. The literature search was conducted in accordance with the PRISMA guidelines. Publication dates extended from January 1998 to February 2021, and were limited to articles published in English. Results: A total of 33 studies were included: 25 studies evaluating thyroid surgery outcomes, 4 studies evaluating parathyroid surgery outcomes, and 4 studies evaluating both thyroid and parathyroid (mixed) surgery outcomes. Higher volume thyroid and parathyroid surgeons were found to be associated with fewer surgical and medical complications, shorter length of hospital stay, and reduced total cost when compared to lower volume surgeons. This volume-outcome relationship was also found to specifically affect the complication and recurrence rates for thyroid cancer patients undergoing surgery, especially for individuals with advanced stage disease. Conclusion: The heterogeneity in cut-offs used for characterizing surgeons as high versus low volume, and also in subsequent patient outcome measures, limited direct study comparisons. The trend of improved patient outcomes with higher surgeon volume for both thyroid and parathyroid surgeries was consistently present in all studies reviewed.