Estimating the Economic and Clinical Value of Introducing Ceftazidime/Avibactam into Antimicrobial Practice in Japan: A Dynamic Modelling Study.

Background: Antimicrobial resistance (AMR) is one of the most serious public health challenges worldwide, including in Japan. Globally, research and development of new antimicrobials has stalled due to unfavorable market conditions, which undervalue antimicrobials. Furthermore, Japan faces the additional challenge of delayed commercialization for a number of recently approved treatments.

Objective: This study aims to examine the impact on AMR of introducing a new anti-infective treatment, ceftazidime/avibactam, into current treatment strategies. It reports the resulting clinical and economic outcomes from the perspective of healthcare payers in Japan.

Methods: A previously published and validated dynamic disease transmission model was adapted to the Japanese setting. The model estimated health economic outcomes for treating three Gram-negative hospital-acquired infections, under different treatment strategies, from a healthcare payers' perspective. Outcomes were assessed over a 10-year time horizon with a willingness-to-pay threshold of ¥5,000,000 (US$45,556) per quality-adjusted life-year (QALY) gained and an annual discount rate of 2% applied to costs and benefits.

Results: Introducing ceftazidime/avibactam in the framework of a diversification strategy with piperacillin/tazobactam is associated with reducing 798,640 bed days, equating to ¥21.0 billion (US$190.9 million) savings in hospitalization costs, and a gain of 363,034 life-years, or 308,641 QALYs. This translates into a monetary benefit of ¥1.56 trillion (US$14.3 billion) to Japanese healthcare payers.

Discussion: Introducing a new antimicrobial agent into clinical practice is associated with considerable clinical and economic benefits. This analysis demonstrates that the approach taken to incorporate a new antimicrobial agent into clinical practice impacts on the scale of these clinical and economic benefits; greater benefits are associated with earlier use of antimicrobials as part of an antimicrobial stewardship program.

Conclusion: This analysis shows that changing the way in which a new antimicrobial is used within a treatment strategy has the potential for additional significant clinical and economic value.