Analysis of variations in the use of intraoperative nerve monitoring in thyroid surgery

Abstract

Importance: Intraoperative nerve monitoring (IONM) is increasingly performed during thyroid surgery. Objective: To examine the use of IONM and its association with patient demographic characteristics and surgeon volume. Design, Setting, and Participants: A cross-sectional analysis used the State Inpatient Databases from January 1, 2010, to December 31, 2011, to assess patient demographic characteristics and surgeon volume. Available 30-day readmission data for all adult patients (aged ≥ 18 years) who underwent thyroidectomy in Florida, New York, and Washington were included. Follow-up was completed on December 31, 2011, and data were analyzed from March 11, 2015, to February 17, 2016. Main Outcomes and Measures: Use of IONM and incidence of postoperative vocal cord paralysis. Results: A total of 17 268 patients undergoing thyroidectomy were included (20.3% men; 79.7% women; mean [SD] age, 53.0 [15.1] years), of whom 1433 patients (8.3%) had IONM. Patients who were significantly less likely to undergo IONM included black patients (185 [7.9%]; adjusted odds ratio [AOR], 0.79; 95%CI, 0.65-0.97) and those with Medicare (382 [8.4%]; AOR, 0.81; 95%CI, 0.69-0.94) or Medicaid (125 [5.5%]; AOR, 0.59; 95%CI, 0.48, 0.74) health coverage. Black patients had a higher prevalence of vocal cord paralysis compared with white patients (37 [1.6%] vs 138 [1.3%]; AOR, 1.64; 95%CI, 1.11-2.43) in a multivariate model that also controlled for IONM use. Low-volume surgeons were more likely to use IONM (1199 [9.2%] vs 234 [5.5%]; AOR, 1.76; 95%CI, 1.48-2.09). However, patients treated by low-volume surgeons had a higher risk for vocal cord paralysis compared with those treated by high-volume surgeons (187 [1.4%] vs 26 [0.6%]; AOR, 2.47; 95%CI, 1.61-3.80). The risk for vocal cord paralysis was not associated with the performance of IONM (AOR, 0.74; 95%CI, 0.48-1.16) or the type of thyroidectomy (AOR, 1.04; 95%CI, 0.75-1.44). Conclusions and Relevance: Disparities in the use of IONM are based on demographic factors of the patients and surgeon volume. Intraoperative nerve monitoring appears to be used less in black patients or those with Medicare health coverage and is not associated with the risk for vocal cord paralysis.