IntroductionThe rising antimicrobial resistance (AMR) and the difficulty in developing new antibiotics are causing a global public health problem. This analysis aims to better understand the clinical and economic value of new antibiotic treatment strategies, in order to inform clinical and antibiotic formulary decisions.MethodsWe applied a published and validated dynamic disease transmission and cost-effectiveness model of AMR with a 10-year time horizon and discount rate of five percent to evaluate the clinical and economic outcomes of introducing a new antibiotic, namely, Ceftazidime/Avibactam (CAZ-AVI) for treating AMR infections in Zhejiang Province, China. Together with piperacillin-tazobactam (pip/taz) and meropenem, we explored the impact of six treatment strategies across three common infections (complicated intra-abdominal infection (cIAI), hospital-acquired/ventilator-associated pneumonia (HAP/VAP) and infections with limited treatment options (LTO)), and pathogens (Escherichia coli, Klebsiella spp., and Pseudomonas aeruginosa). These treatment strategies included (i) current treatment strategy (pip/taz and meropenem, no CAZ-AVI), (ii) CAZ-AVI at the third line, (iii) CAZ-AVI at the second line, (iv) CAZ-AVI at the first line, (v) first line diversity (i.e., equal pip/taz and CAZ-AVI at the first line; meropenem at the last line) and (vi) all-lines diversity (pip/taz, meropenem and CAZ-AVI used randomly and only once). The data with a total of 10,905 patients were collected from a tier-3 hospital from 2018 to 2021.ResultsUnder the current treatment strategy, the hospital length of stay (LOS) and costs over ten years were estimated to be 1,588,763 days and CNY3,898,198,802 (USD559,781,348), respectively, associated with 142,999 quality-adjusted life-years (QALYs) lost, resulting in the resistance of pip/taz and meropenem being 42.0 percent and 49.9 percent respectively. In contrast, the other five treatment strategies all have shown improved outcomes, among which the “all-lines diversity” carried the greatest benefit, saving CNY1,646.04 (USD236.37) for each additional QALY gained, with the net monetary benefit being CNY24,727,102,215 (USD3,550,811,878).ConclusionsIntroducing CAZ-AVI had positive impact on clinical and economic outcomes for treating AMR, and diversifying early the antibiotics might yield the best benefits.