Economic evaluation is a type of comparative analysis between interventions in terms of both their resource use and health outcomes. Due to the good prognosis of thyroid cancer (TC), the socioeconomic burden of TC patients post-diagnosis is increasing. Therefore, economic evaluation studies focusing on TC are recommended. This study aimed to describe the concept and methods of economic evaluation and reviewed previous TC studies. Several previous studies compared the costs of interventions or evaluated recurrence, complications, or quality of life as measures of their effectiveness. Regarding costs, most studies focused on direct costs and applied hypothetical models. Cost-minimization analysis should be distinguished from simple cost analysis. Furthermore, due to the universality of the term “cost-effectiveness analysis” (CEA), several studies have not distinguished CEA from cost-utility analysis; this point needs to be considered in future research. Cost-benefit analyses have not been conducted in previous TC research. Since TC has a high survival rate and good prognosis, the need for economic evaluations has recently been pointed out. Therefore, correct concepts and methods are needed to obtain clear economic evaluation results. On this basis, it will be possible to provide appropriate guidelines for TC treatment and management in the future.

Background: This systematic review was conducted to identify and summarize key factors, including economic methods, topics, results, and indicators, within relevant economic evaluation research on thyroid cancer. Materials and Methods: A literature search on the economic evaluation of thyroid cancer treatment was conducted using the MEDLINE database up to May 2021. Data on population, intervention, comparison, outcome, time, setting, and study design were extracted from each study. The economic evaluation method in each study was re-classified according to the theoretical criteria defined by the international economic evaluation guidelines. Results: A total of 49 studies were included, involving cost analysis (CA, n=9), cost-minimization analysis (CMA, n=3), cost-effectiveness analysis (CEA, n=29), and cost-utility analysis (CUA, n=8). When CEA and CUA were classified as one method, the consistency between the methods of the reviewers based on the theoretical criteria and those from the original studies was 77% (95% confidence interval, 0.63-0.92). Most studies dealt with specific period-related controversial issues including comparison between treatment strategies, and cost-effectiveness of the prophylactic central neck dissection, molecular testing, and rhTSH. Contrasting results have been obtained when different economic evaluation methods were applied for the same topic (e.g., total thyroidectomy [TT] was more dominant than hemithyroidectomy [HT] in CEA, but HT was more dominant than TT in CUA), and different clinical and economic inputs were applied. All studies included direct medical costs, which were mostly derived from Medicare and input probabilities in each economic model, and utility scores for outcomes were mostly based on literature reviews. Few studies included non-medical direct costs and indirect costs. Conclusion: Our systematic review provides information on how to design and proceed to overcome the limitations of existing studies and ensure validity.