Estimating the value of new antibiotic treatment strategies in Zhejiang province, China: cost-effectiveness analysis based on a validated dynamic model.

Objectives: This analysis aims to better reflect the value of new antibiotic treatment strategies, thereby informing clinical antibiotic use, antimicrobial reimbursement and/or hospital formulary decision-making in China.

Design: We adapted a published and validated dynamic disease transmission and cost-effectiveness model to evaluate the clinical and economic outcomes of introducing a new antibiotic, ceftazidime/avibactam (CAZ-AVI) for treating resistant infections in Zhejiang province, China. Outcomes were assessed over a 10-year infectious period and an annual discount rate of 5%. Costs were extracted from the hospital's Health Information System (HIS) and obtained after data cleaning, aggregation and discounting.

Setting: The Chinese healthcare system perspective.

Participants: 10 905 patients in a Chinese tier-3 hospital from 2018 to 2021 with any of the three common infections (complicated intra-abdominal infection (cIAI), hospital-acquired/ventilator-associated pneumonia (HAP/VAP) and infections with limited treatment options (LTO)) caused by three common resistant pathogens ( spp. ).

Interventions: (1) Current treatment strategy (piperacillin-tazobactam (pip/taz) and meropenem); (2) CAZ-AVI at the third line; (3) CAZ-AVI at the second line; (4) CAZ-AVI at the first line; (5) CAZ/AVI first line, two lines diversified (i.e., equal pip/taz and CAZ-AVI at the first line; meropenem at the last line) and (6) CAZ/AVI first line, all-lines diversified.

Primary Outcome Measures: Quality-adjusted life years (QALYs) lost, hospitalisation costs and incremental net monetary benefit (INMB) were used to assess cost-effectiveness.

Results: Over 10 years, the introduction of CAZ-AVI to the current treatment strategy led to lower hospitalisation costs and more QALYs across all five treatment strategies, with between 68 284 and 78 571 QALYs gained whilst saving up to US$236.37 for each additional QALY gained. The INMB of introducing CAZ-AVI is estimated up to US$3 550 811 878.

Conclusions: Introducing CAZ-AVI had a positive impact on clinical and economic outcomes for treating antimicrobial resistance, and diversifying the antibiotics use early in the treatment might yield the best benefits.