High Rates of Unnecessary Surgery for Indeterminate Thyroid Nodules in the Absence of Molecular Test and the Cost-Effectiveness of Utilizing Molecular Test in an Asian Population: A Decision Analysis

Objectives: Cytologically indeterminate thyroid nodules (Bethesda class III or IV) carry a 10-40% risk of malignancy. Diagnostic lobectomies are frequently performed but negative surgeries incur unnecessary costs on the healthcare system, potential complications, and negative impacts on quality of life. Molecular tests (MTs) have been developed to reduce unnecessary surgeries. However, well-validated, high-performance MTs are often expensive, and their cost-effectiveness has not been studied in the Asian population. This study evaluates the rate of unnecessary surgery in the setting without MT (our current practice) and the cost-effectiveness of introducing a commercially available MT for the management of cytologically indeterminate thyroid nodules in a modernized city in Asia. Methods: Management decisions and outcomes of consecutive Bethesda III or IV thyroid nodules in a tertiary endocrine surgery center in Hong Kong were evaluated. Costs of health service provided by the public health system, which covers >90% of healthcare service in the city, were retrieved. A decision tree model was developed to compare the cost-effectiveness in avoiding unnecessary surgeries of current practice versus routine MT from a public healthcare provider's perspective. In our current practice, MT was not available, and patients with indeterminate nodules received either upfront lobectomy, repeat fine needle aspiration cytology (FNAC), or active surveillance. Results: Over a 4-year period, 2157 FNACs were performed. After exclusion, 1957 FNACs were analyzed, and 18.6% were Bethesda III or IV. Thirty-six percent of these cytologically indeterminate nodules received upfront surgery, with 28% having malignancy in final pathology, that is, 72% of surgeries were unnecessary. Routine MT could reduce 82 unnecessary surgeries/year, 26% more than current practice. Routine MT resulted in an incremental cost-effectiveness ratio of Hong Kong dollar (HKD) 49,102 (US dollar [USD] 6314) per unnecessary surgery. Sensitivity analysis showed test cost of MT contributed significantly to incremental cost-effectiveness ratio. Lowering the commercial price of MT to below HKD 8044 (USD 1031) would render routine MT cost-saving. Conclusion: Currently, a high rate of unnecessary surgeries is being performed for cytologically indeterminate thyroid nodules. MT was more effective in reducing unnecessary surgeries than current practice, but at a higher cost. MT will become cost-saving if the test cost could be lowered.