Cost-Effectiveness Analysis of Molecular Testing for Indeterminate Thyroid Nodules in Nova Scotia.

Background: The objective of the following retrospective review was to perform a cost-effectiveness analysis of the use of molecular testing of indeterminate thyroid nodules compared to current management practices in Nova Scotia, Canada.

Methods: All cases of cytologically indeterminate thyroid nodules from January 1st, 2014 to December 31st, 2018 were reviewed. All interventions related to an indeterminate thyroid nodule were recorded. Patients were excluded if less than 18 years old if no further information regarding medical management was electronically available beyond the diagnosis of an indeterminate thyroid nodule, history of radiation, or previous thyroid surgery prior to diagnosis of an indeterminate thyroid nodule in the remaining lobe. Microcosting was performed to determine the cost of all relevant interventions including repeat fine needle aspiration biopsy, ultrasound, thyroid surgery(s), and molecular testing. Institution-specific transition state probabilities were calculated and used to build a cost-effectiveness analysis model. Model output was an incremental cost-effectiveness ratio, defined as the ratio of cost difference to effectiveness difference between routine molecular testing and the current management strategy, yielding cost per surgery avoided.

Results: The mean effectiveness of the current management of indeterminate thyroid nodules in Nova Scotia based on the American Thyroid Association guidelines is 64% at a mean cost of $6431, while the simulated mean effectiveness of routine molecular testing is 89% at a mean cost of $8414. Differences in management strategies generated an incremental cost-effectiveness ratio of $7876 per surgery avoided.

Conclusion: Routine molecular testing is the more effective strategy for the appropriate management of indeterminate thyroid nodules; however, it comes at a higher mean cost compared to the current management strategy. As the cost of molecular testing continues to decrease, and the cost of OR resources continues to rise, molecular testing is likely to become the optimal strategy in Nova Scotia.