■ 学会名
ISPOR Real-World Evidence Summit 2025

■ 発表日
2025/09/29

■ 筆頭演者
Kazuhiko Takahata¹
1) Department of Public Health and Epidemiology, Meiji Pharmaceutical University, Tokyo, Japan

■ 共同演者
Eiichi Tanaka², Ryoko Sakai¹, Manabu Akazawa¹
1) Department of Public Health and Epidemiology, Meiji Pharmaceutical University, Tokyo, Japan
2) Department of Rheumatology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan

■ 発表形態
Poster

■ 要旨
OBJECTIVES: Biological disease-modifying antirheumatic drugs (bDMARDs) are effective treatments for rheumatoid arthritis (RA), however, their high cost is a significant concern. Self-injection (SI) of bDMARDs may reduce the frequency of hospital visits and associated costs, but its overall economic impact remains unclear. This study evaluated the effect of SI on healthcare costs from a societal perspective.
METHODS: A cost of illness model was developed using real-world data from a Japanese claims database (DeSC Healthcare), patient survey data (Medilead Inc.), and publicly available government sources. Patients with RA using SI (SI group) were compared with those not using SI (non-SI group). Direct healthcare costs (e.g., drug costs, consultation fees), direct non-healthcare costs (e.g., travel costs), and indirect costs (e.g., productivity loss) were estimated. Annual costs were calculated for both groups, and sensitivity analyses were conducted based on travel
costs and hourly wage assumptions.
RESULTS: Annual total healthcare costs were higher in the SI group (10,065 USD) than in the non-SI group (7,963 USD), using an exchange rate of 150 yen per USD. This difference was mainly due to higher bDMARD costs in the SI group, where patients received an average of 3 prescriptions (726 USD/month) compared to 2 prescriptions (501 USD/month) in the non-SI group. Although the SI group had fewer hospital visits (9.5 vs. 25 per year), total healthcare costs per visit were higher. Other cost categories (e.g., other disease-modifying antirheumatic drugs, examination and rehabilitation) were similar between the groups. Sensitivity analyses indicated that SI could become cost-saving if travel costs per visit exceeded 139 USD or hourly wages exceeded 80 USD.
CONCLUSIONS: Although SI of bDMARD may involve higher direct medical costs, it has the potential to be advantageous in terms of overall societal costs by reducing work-related and caregiving burdens.