High Suspicion Sub-Centimeter Thyroid Nodules: Cost-Effectiveness of Active Surveillance versus Fine Needle Aspiration.

Abstract

PurposeTo compare the cost-benefit of active surveillance (AS) against immediate fine needle aspiration (FNA) of sonographically suspicious sub-centimeter thyroid nodules.MethodsA Markov model was constructed to compare the cost-benefit of three strategies from point of discovery till death: 1) Surveillance of All Nodules; 2) Surveillance of Nodules with Positive Cytology; and 3) Surgery of Nodules with Positive Cytology. The reference case was a 40 year-old female with a sonographically suspicious sub-centimeter thyroid nodule. Transition probabilities, costs, and health utilities were derived from the literature. Sensitivity analyses were performed to evaluate model uncertainty. Willingness-to-pay threshold was set at $100,000/quality-adjusted life year (QALY).ResultsSurveillance of Nodules with Positive Cytology dominated in the reference scenario, and was cost-beneficial over Surveillance of All Nodules independent of the utility of AS. Surveillance of All Nodules was cost-beneficial only at life expectancy <2.6 years or surveillance duration <4 years.ConclusionWhile current guidelines recommend AS of sonographically suspicious sub-centimeter nodules, this study's results suggest immediate FNA (Surveillance of Nodules with Positive Cytology) is more cost-beneficial compared to AS (Surveillance of All Nodules). Patients with positive cytology on FNA may subsequently opt for AS (Surveillance of Nodules with Positive Cytology) or surgery (Surgery of Nodules with Positive Cytology) according to their level of comfort (i.e. utility) with AS.