Thyroidectomy Practice After Implementation of the 2015 American Thyroid Association Guidelines on Surgical Options for Patients With Well-Differentiated Thyroid Carcinoma.

IMPORTANCE The recommended extent of surgery for well-differentiated thyroid carcinoma has been modified considerably in the updated 2015 American Thyroid Association guidelines published in January 2016. To date, the changes in clinical practice after publication of these new guidelines have not been demonstrated. OBJECTIVE The aim of this study was to evaluate clinical practice changes associated with implementation of the updated guidelines on the surgical procedure rates of total thyroidectomy, thyroid lobectomy, and completion thyroidectomy at a single tertiary medical center. DESIGN, SETTING, AND PARTICIPANTS This is a retrospective cohort study of 169 patients at the Hadassah-Hebrew University Medical Center, Jerusalem, Israel. Patients with pathologically proved, well-differentiated thyroid carcinoma who underwent surgery between January 1, 2013, and December 31, 2014, were compared with patients who underwent surgery from January 1 to December 31, 2016. A total of 434 thyroidectomy procedures were performed during the study period, and 251 had pathologically proved, well-differentiated thyroid carcinoma. Patients with tumors larger than 4 cm, involved lymph nodes, or bilateral nodules were excluded. MAIN OUTCOMES AND MEASURES Primary outcomes were the rate of up-front total thyroidectomy vs lobectomy and the rates of completion thyroidectomy before and after the implementation of the new guidelines. RESULTS Of the 169 patients in the final analysis, 118 (69.8%) were included from 2013 to 2014 and 51 (30.2%) in 2016. The mean (SD) age for the entire cohort was 44 (13.8) years, and 129 (76.3%) were women. Up-front total thyroidectomy was performed in 72 of 118 patients (61.0%) prior to the 2015 American Thyroid Association guidelines and 16 of 51 (31.4%) following their implementation (odds ratio, 0.29; 95% CI, 0.14-0.59). The rate of completion thyroidectomy also significantly decreased between these periods (73.9% vs 20.0%; odds ratio, 0.09; 95% CI, 0.04-0.19). CONCLUSIONS AND RELEVANCE The updated 2015 American Thyroid Association guidelines implementation was associated with a significant decrease in the rates of both up-front total thyroidectomy and completion thyroidectomy. According to these findings, only 1 of 5 patients who undergoes thyroid lobectomy will require a completion procedure.