To determine the number of total thyroidectomies per surgeon per year associated with the lowest risk of complications.
The surgeon volume–outcome association has been established for thyroidectomy; however, a threshold number of cases defining a “high-volume” surgeon remains unclear.
Adults undergoing total thyroidectomy were identified from the Health Care Utilization Project-National Inpatient Sample (1998–2009). Multivariate logistic regression with restricted cubic splines was utilized to examine the association between the number of annual total thyroidectomies per surgeon and risk of complications.
Among 16,954 patients undergoing total thyroidectomy, 47% had thyroid cancer and 53% benign disease. Median annual surgeon volume was 7 cases; 51% of surgeons performed 1 case/y. Overall, 6% of the patients experienced complications. After adjustment, the likelihood of experiencing a complication decreased with increasing surgeon volume up to 26 cases/y (P
< 0.01). Among all patients, 81% had surgery by low-volume surgeons (≤25 cases/y). With adjustment, patients undergoing surgery by low-volume surgeons were more likely to experience complications (odds ratio 1.51, P
= 0.002) and longer hospital stays (+12%, P
= 0.006). Patients had an 87% increase in the odds of having a complication if the surgeon performed 1 case/y, 68% for 2 to 5 cases/y, 42% for 6 to 10 cases/y, 22% for 11 to 15 cases/y, 10% for 16 to 20 cases/y, and 3% for 21 to 25 cases/y.
This is the first study to identify a surgeon volume threshold (>25 total thyroidectomies/y) that is associated with improved patient outcomes. Identifying a threshold number of cases defining a high-volume thyroid surgeon is important, as it has implications for quality improvement, criteria for referral and reimbursement, and surgical education.