Radioiodine or Surgery for Toxic Thyroid Adenoma: Dissecting an Important Decision. A Cost-Effectiveness Analysis

OBJECTIVE: To examine the cost effectiveness of therapeutic strategies for toxic thyroid adenoma. DESIGN: Markov state transition decision analytic model. SETTING: Ambulatory and inpatient. PATIENTS: Hypothetical cohort of 40- year-old women with toxic thyroid adenomas. Patient age was varied in sensitivity analyses. Data on the prevalence of coincident thyroid cancer, complications, and treatment efficacies were derived from a systematic review of the literature. INTERVENTIONS: Thyroid lobectomy after a 3 month-course of antithyroid drugs (ATDs), high-dose (<555 MBq) radioactive iodine (RAI), low-dose (>555 MBq) RAI, and lifelong ATDs. MEASUREMENTS AND MAIN RESULTS: Outcomes were measured in quality-adjusted life years (QALYs). Costs were estimated from the health care system perspective. Future costs and effectiveness were discounted at 3% per year. For a 40- year-old woman, surgery was the most effective, while low-dose RAI was the least costly. The marginal cost-effectiveness of surgery versus low-dose RAI was $13,183 per QALY. Surgery was less costly and more effective than lifelong ATDs. RAI was more effective than surgery if surgical mortality exceeded 0.90% (base-case 0.001%). Surgery provided relatively inexpensive gains (<$50,000 per QALY) in quality-adjusted life expectancy in patients less than 74 years of age. CONCLUSIONS: For most patients less than 60 years of age, surgery is an effective strategy with a reasonable cost. However, for any given patient, surgical mortality, therapeutic costs and preference must be considered in choosing an appropriate therapy.