The cost-effectiveness of iodine 131 scintigraphy, ultrasonography, and fine-needle aspiration biopsy in the initial diagnosis of solitary thyroid nodules.

OBJECTIVE To compare the cost-effectiveness of fine-needle aspiration biopsy, iodine 131 scintigraphy, and ultrasonography for the initial diagnostic workup of a solitary palpable thyroid nodule. DESIGN A deterministic cost-effectiveness analysis was conducted using a decision tree to model the diagnostic strategies. SETTING A single, mid-Atlantic academic medical center. MAIN OUTCOME MEASURES Expected costs, expected number of cases correctly diagnosed, and incremental cost per additional case correctly diagnosed. RESULTS Relative to the routine use of fine-needle aspiration biopsy, the incremental cost per case correctly diagnosed is 24,554 dollars for the iodine 131 scintigraphy strategy and 1212 dollars for the ultrasound strategy. CONCLUSIONS A diagnostic strategy using initial fine-needle aspiration biopsy for palpable thyroid nodules was found to be cost-effective compared with the other approaches as long as a payor's willingness to pay for an additional correct diagnosis is less than 1212 dollars. Prospective studies are needed to validate these finding in clinical practice.