BACKGROUND:Antimicrobial resistance is a critical public health issue. Greece has the second highest percentage of antimicrobial resistance in the European Union reporting an endemic of carbapenemase-producing Enterobacterales infections like K. pneumonia producing KPC.

OBJECTIVES: The present study assesses the cost-effectiveness of imipenem/cilastatin/relebactam (Imi/Rel) for the treatment of complicated intra-abdominal infections (cIAI), complicated urinary tract infections (cUTI) including pielonephritis, and hospital-acquired and ventilator-associated bacterial pneumonia (HABP/VABP) caused by carbapenem resistant (CR) Gram-negative (GN) bacteria in Greece.

METHODS: The adaptation was performed from the payer’s perspective. The model includes data from the RESTORE-IMI-1 trial and consists of two parts: a decision-tree, depicting the period from diagnosis to hospital discharge and a Markov model, projecting long-term outcomes and costs following hospital discharge. The model includes a population of patients distributed among three afore-mentioned disease categories with confirmed CR-pathogens. The model projects costs and outcomes within a 45-years’ time horizon, costs and LYs are discounted at an annual rate of 3.5%. Outcomes included Life Years (LY’s) as well as resource use and mortality for each comparator . A deterministic sensitivity analysis (DSA) was performed to identify the input parameters impact on ICER, and a Probabilistic Sensitivity Analysis (PSA) was run to examine the robustness against collective uncertainty of all parameters. Comparators in the model include piperacillin-Tazobactam (pip/tazo) and imipenem/cilastatin (Imi).

RESULTS:

Imi gives 18.14, Pip/Tazo gives 20 additional LY’s whereas Imi/Rel yields 22 LY’s. Imi/Rel showed an incremental cost-effectiveness ratio of 1812€ per LY gained compared to Pip/Tazo and 211€ per LY gained compared to imi. The PSA showed in 94.5% of the 5,000 simulations imi/rel being cost-effective versus Imi under the Greek willingness-to-pay threshold of 52,770 €/QALY.

CONCLUSIONS: This study suggests that Imi/Rel is a cost-effective treatment option for patients with (cIAI), (cUTI), and (HABP/VABP) caused by CR GN bacteria in Greece.