The ICD-10 codes used in this study.

<div><p>Background</p><p>Biosimilars have the potential to save a significant amount of money in cancer treatment costs. However, barriers exist in the adoption of biosimilar products. Japan introduced a new health policy in 2022 to promote the use of biosimilars in oncology by offering financial incentives to eligible hospitals. This study aims to examine the association between these financial incentives and prescription patterns.</p><p>Methods</p><p>The study analyzed Diagnosis Procedure Combination (DPC) data to assess the impact of the new health policy on the use of biosimilar products in oncology. The policy provided an additional fee for hospitals using biosimilar products. The study included patients with specific types of cancer and analyzed the proportion of monthly biosimilar prescriptions using the number of prescriptions of reference and biosimilar products. A generalized synthetic control method was used for analysis.</p><p>Results</p><p>From April 2020 to March 2023, the study involved 27,737 patients in 114 hospitals, with 63 eligible hospitals receiving financial incentives. The average number of prescriptions of the drugs (rituximab, trastuzumab, and bevacizumab) increased gradually in both eligible and ineligible hospitals. The financial incentives were associated with a significant increase in the proportion of biosimilar product prescriptions, with a monthly increase of 0.092 per month (95% CI, 0.040–0.145) [9.2%, 95% CI, 4.0–14.5] compared to ineligible hospitals.</p><p>Conclusion</p><p>Our study indicates that providing financial incentives to hospitals to utilize biosimilar products increased their prescriptions. Japan’s recent health policy of moderate financial incentives is an effective approach to increasing prescriptions of biosimilar products.</p></div>