Cost-effectiveness analysis comparing repetitive transcranial magnetic stimulation therapy with antidepressant treatment in patients with treatment-resistant depression in Japan

Background: In Japan, repetitive transcranial magnetic stimulation (rTMS) for patients with treatment-resistant depression (TRD) became covered by the National Health Insurance (NHI) in 2019. While the usefulness of rTMS for TRD has been established, the cost-effectiveness of rTMS versus antidepressants has not been thoroughly analyzed in Japan. This study aimed to evaluate the cost-effectiveness of rTMS for TRD under the NHI system. Methods: Cost-effectiveness of rTMS versus antidepressants was analyzed using a microsimulation model to compare the direct costs and quality-adjusted life years (QALYs) in patients with moderate to severe depression who had failed one or more antidepressants over their lifetime. Model inputs of clinical parameters and the utility were derived from published literature. Cost parameters were estimated from the Japanese Claim Database. In addition, the robustness of the analysis results was evaluated using sensitivity analysis and scenario analysis. Results: The analysis estimated that rTMS increased effectiveness by 0.101QALYs and total cost by {yen}94,370 ($689) compared with antidepressant medications. As a result, the incremental cost-effectiveness ratio (ICER) of rTMS was estimated to be {yen}935,984 ($6,832)/QALY. In the sensitivity and scenario analyses, ICER did not exceed {yen}5 million ($36,496)/QALY as the reference value of the Japanese public cost-effectiveness evaluation system. Limitations: For the portion of the rTMS for which data were not available under the NHI system in Japan, foreign data and estimates were extrapolated. Conclusions: rTMS showed the potential to be a cost-effective treatment strategy for TRD compared with antidepressants under the NHI system in Japan.