Each procedure matters: threshold for surgeon volume to minimize complications and decrease cost associated with adrenalectomy

Background. An association has been suggested between increasing surgeon volume and improved patient outcomes, but a threshold has not been defined for what constitutes a high-volume adrenal surgeon. Methods. Adult patients who underwent adrenalectomy by an identifiable surgeon between 19982009 were selected from the Healthcare Cost and Utilization Project National Inpatient Sample. Logistic regression modeling with restricted cubic splines was utilized to estimate the association between annual surgeon volume and complication rates in order to identify a volume threshold. Results. A total of 3,496 surgeons performed adrenalectomies on 6,712 patients; median annual surgeon volume was 1 case. After adjustment, the likelihood of experiencing a complication decreased with increasing annual surgeon volume up to 5.6 cases (95% confidence interval, 3.27-5.96). After adjustment, patients undergoing resection by low-volume surgeons (<6 cases/year) were more likely to experience complications (odds ratio 1.71, 95% confidence interval, 1.27-2.31, P = .005), have a greater hospital stay (relative risk 1.46, 95% confidence interval, 1.25-1.70, P =.003), and at increased cost (+26.2%, 95% confidence interval, 12.6-39.9, P = .02). Conclusion. This study suggests that an annual threshold of surgeon volume (6 cases/year) that is associated with improved patient outcomes and decreased hospital cost. This volume threshold has implications for quality improvement, surgical referral and reimbursement, and surgical training. (C) 2017 Elsevier Inc. All rights reserved.