Effect of a financial incentive scheme on promoting prescription of biosimilars: a interrupted time-series analyses

抄録

BACKGROUND

In Japan, biosimilars have the potential to reduce drug expenditure because their official price is lower than the price of the original products. To promote biosimilars, the Japanese government introduced a new financial incentive scheme for medical institutions to prescribe biosimilars to outpatients in April 2020. However, the impact of the incentive remains unevaluated. Hence, in this study, we conducted an interrupted time-series analysis to evaluate the impact of the incentive scheme on biosimilar prescription.

METHODS

We used the DeSC database in Japan. From this database, we included 3,348 patients who required self-injection and were prescribed insulin, human growth hormone, or etanercept. Interrupted time-series analyses were conducted by fitting Prais–Winsten linear regression models to assess the association of the financial incentive with the outcomes, namely, monthly proportions of biosimilar prescriptions between April 2019 and March 2021.

RESULTS

No significant changes were observed in the monthly proportion of biosimilar prescriptions immediately after the introduction of the incentive. The sustained effect, representing the effect of the intervention over time, was also not significant.

CONCLUSIONS

Our study suggests that the financial incentive introduced in April 2020 in Japan was not associated with an increase in biosimilar prescriptions.