Pharmacoeconomic analysis of biologics and methotrexate for rheumatoid arthritis from the standpoint of the number needed to treat concept under the Japanese health insurance system

OBJECTIVES: To evaluate the cost-effectiveness of biologics and methotrexate (MTX) for rheumatoid arthritis (RA) using the number needed to treat (NNT) concept and total actual health care cost. METHODS: This study included 121 RA patients with newly prescribed biologics and/or MTX between 2012 and 2017. The NNT was calculated based on the 24 week remission rate of Disease Activity Score in 28 joints using erythrocyte sedimentation rate (DAS28-ESR) and Clinical Disease Activity Index (CDAI). RESULTS: Remission rates were 76.4% for DAS28-ESR and 45.4% for CDAI in the biologics group and 63.6% and 24.2%, respectively, in the MTX group. The NNT was calculated as 6.4 and 4.2 in the biologics group and 34.2 and 35.2 in the MTX group, respectively. Mean total actual health care costs were 1,044,066 JPY (9835 US$)/24 weeks per treated patient in the biologics group and 75,860 JPY (715 US$)/24 weeks in the MTX group. Although the effectiveness of biologics was superior to MTX from the standpoint of NNT, the mean total health care cost and mean cost per NNT were much higher in the biologics group. CONCLUSIONS: Cost-effectiveness is clearly higher for MTX than biologics from the standpoint of mean total health care cost per adjusted NNT under the Japanese health insurance system.