Cost-Effectiveness of Molecular Testing for Thyroid Nodules With Atypia of Undetermined Significance Cytology

Context: Novel molecular diagnostics, such as the gene expression classifier (GEC) and gene mutation panel (GMP) testing, may improve the management for thyroid nodules with atypia of undetermined significance (AUS) cytology. The cost-effectiveness of an approach combining both tests in different practice settings in North America is unknown. Objective: The aim of the study was to determine the cost-effectiveness of two diagnostic molecular tests, singly or in combination, for AUS thyroid nodules. Design and Setting: We constructed a microsimulation model to investigate cost-effectiveness from US (Medicare) and Canadian healthcare system perspectives. Patients: Low-risk patients with AUS thyroid nodules were simulated. Interventions: We examined five management strategies: 1) routine GEC; 2) routine GEC + selective GMP; 3) routine GMP; 4) routine GMP + selective GEC; and 5) standard management. Main Outcome Measures: Lifetime costs and quality-adjusted life-years were measured. Results: From the US perspective, the routine GEC + selective GMP strategy was the dominant strategy. From the Canadian perspective, routine GEC + selective GMP cost and additional CAN$24 030 per quality-adjusted life-year gained over standard management, and was dominant over the other strategies. Sensitivity analyses reported that the decisions from both perspectives were sensitive to variations in the probability of malignancy in the nodule and the costs of the GEC and GMP. The probability of cost-effectiveness for routine GEC + selective GMP was low. Conclusions: In the US setting, the most cost-effective strategy was routine GEC + selective GMP. In the Canadian setting, standard management was most likely to be cost effective. The cost of these molecular diagnostics will need to be reduced to increase their cost-effectiveness for practice settings outside the United States.