Cost effectiveness of immediate biopsy versus surveillance of intermediate-suspicion thyroid nodules

In an effort to reduce overdiagnosis of low-risk thyroid cancer, recent clinical guidelines increased the size-based biopsy thresholds for thyroid nodules. The cost-effectiveness of these guidelines is largely unknown. We hypothesized that ultrasound surveillance in lieu of immediate fine needle aspiration biopsy would be cost effective for a 1.0 cm thyroid nodule with American Thyroid Association Intermediate Suspicion sonographic features.

A Markov transition-state model was constructed to compare immediate fine needle aspiration versus ultrasound surveillance. Univariate and multivariate sensitivity analyses were used to examine the uncertainty of cost, probability, and utility estimates in the model.

Ultrasound surveillance was $1,829 less costly and 0.016 quality-adjusted life years more effective than immediate fine needle aspiration. Immediate fine needle aspiration became cost effective when the probability of malignancy increased from 15% to 84% or the cost of ultrasound increased from $129 to $793. Immediate fine needle aspiration was cost-effective if the quality adjustment factor for observation following a benign fine needle aspiration result exceeded the quality adjustment factor for observation without a biopsy.

Ultrasound surveillance is more cost-effective than immediate fine needle aspiration for 1.0 cm thyroid nodules with an intermediate-suspicion sonographic pattern. Additional investigation of health-related quality of life in patients undergoing fine needle aspiration or surveillance is necessary.