Nationwide Variation in Rates of Thyroidectomy Among US Medicare Beneficiaries.

Importance: Research on variation in rates of procedures across otherwise similar geographic regions provides vital insight into practice patterns. It reveals the degree of consensus on how a particular condition is managed, shows areas where access to care may be inadequate, and other areas where the population may be receiving inappropriately high levels of care.
Objective: To test the hypothesis that rates of thyroid surgery vary across US geographic regions.
Design, Setting, and Participants: A cross-sectional analysis of Medicare data for 15 888 beneficiaries aged 65 years or older from 2014 was carried out.
Main Outcome and Measures: Overall and hospital referral region-specific thyroidectomy rate per 100 000 Medicare beneficiaries.
Results: In 2014, 15 888 thyroidectomies were performed on Medicare beneficiaries in the United States (partial n = 7506, total n = 8382), representing a national average rate of 60 per 100 000 beneficiaries (median, 59 per 100 000 beneficiaries; IQR, 43-70 per 100 000). A 6.2-fold difference in thyroidectomy rates was observed across US regions (range, 22-139 per 100 000 Medicare beneficiaries).
Conclusions and Relevance: Thyroidectomy rates in the United States vary 6.2 fold, more than prostatectomy rates, which are usually held as the example of the procedure with the widest variation in the United States. This wide variation in thyroidectomy rates observed among Medicare beneficiaries suggests widely divergent local beliefs and practice patterns surrounding the management of thyroid nodules and cancer because rates appeared to be unrelated to health care availability, regional socioeconomic status, or surgeons per capita. A better understanding for the reasons underlying this variation is needed.