Cost Effectiveness of Definitive Treatment Strategies for Autonomously Functioning Thyroid Nodules

Objective

Autonomously functioning thyroid nodules (AFTN) can be treated with antithyroid drugs, radioactive iodine (RAI), thyroid lobectomy or radiofrequency ablation (RFA). Although surgery is most definitive, some patients require lifelong hormone supplementation. RFA avoids this sequela, but its efficacy depends on nodule size. This study aims to compare the relative cost-effectiveness of RAI, RFA and lobectomy for treatment of AFTNs.

Study Design

A Markov analysis model was created to simulate clinical outcomes, costs and utilities for three AFTN treatments: (1) thyroid lobectomy, (2) RAI, and (3) RFA.

Patients

This mathematical model was created using published literature and modeling.

Measurements

Transition probabilities, utilities and costs were extracted from published literature, Medicare, and RedBook. The willingness to pay threshold was set to $100,000 per quality-adjusted life year. The model simulated 2-year outcomes, reflecting RFA literature. Sensitivity analyses were conducted to account for uncertainty in model variables.

Results

In the base model, RAI dominated both lobectomy and RFA, with lower estimated cost ($2000 vs. $9452 and $10,087) and higher cumulative utility (1.89 vs. 1.82 and 1.78 quality-adjusted life years). One-way sensitivity analyses demonstrated that relative cost-effectiveness between surgery and RFA was driven by the probability of euthyroidism after RFA and hypothyroidism after lobectomy. RFA becomes more cost-effective than surgery if the rate of euthyroidism after ablation is higher than 69% (baseline 54%).

Conclusion

Based on published data, RAI is most cost-effective in treating most AFTN. Surgery is more cost-effective than RFA in most scenarios, but RFA may be more resource-efficient for smaller nodules with a high likelihood of complete treatment.