Cost-effectiveness of empirical ceftazidime-avibactam for hospital-acquired urinary tract infections: a modeling study identifying key beneficiary subgroups

Hospital-acquired urinary tract infections (HAUTIs) caused by Gram-negative bacilli are increasingly difficult to manage owing to rising carbapenem resistance. The novel antibiotic ceftazidime-avibactam (CAZ-AVI) is a potential alternative, but its cost-effectiveness in this setting is unknown. This study evaluated the cost-effectiveness of empirical CAZ-AVI versus a meropenem-first strategy for treating HAUTIs. Using a patient-level decision-tree model, we simulated adult patients with HAUTIs in general ward and intensive care unit (ICU) settings in Taiwan, drawing on local pathogen distribution and antimicrobial susceptibility data. The model compared total costs and quality-adjusted life-years (QALYs); in the meropenem arm, pathogen-susceptible cases underwent antibiotic de-escalation once culture-guided susceptibility results were available. Clinical outcomes, utility weights, and costs were obtained from secondary sources of published studies, with all costs expressed in 2024 U.S. Dollars (USD) and future QALYs discounted at 3% annually. The primary outcome was the incremental cost-effectiveness ratio (ICER) per QALY gained, evaluated against a willingness-to-pay (WTP) threshold equal to Taiwan’s 2024 GDP per capita ($33,983/QALY). Uncertainty was assessed with one-way, probabilistic, and scenario sensitivity analyses. In the base case, CAZ-AVI was cost-effective in both settings. Incremental cost-effectiveness ratios (ICERs) were $12,049/QALY (Ward) and $21,396/QALY (ICU), both below the WTP threshold. At Taiwan’s WTP threshold, the probability that CAZ-AVI was cost-effective was 93.8% (Ward) and 76.9% (ICU). The 50% cost-effectiveness threshold was approximately $12,500/QALY (Ward) and $22,500/QALY (ICU). In scenario analysis, CAZ-AVI was dominant (more effective and cost-saving) for patients with end-stage renal disease (ESRD). Empirical CAZ-AVI is cost-effective compared with meropenem for HAUTIs in both ward and ICU settings in Taiwan, with benefits most pronounced in critically ill patients and those with severe renal impairment. These findings support CAZ-AVI as a first-line empirical option in select patient populations, particularly in institutions with elevated rates of meropenem-resistant pathogens and may inform local antimicrobial stewardship policy.