OBJECTIVES

To compare the cost-effectiveness of ceftazidime-avibactam (CAZ-AVI) to current treatments for intra-abdominal infections (IAI) due to carbapenem resistant Enterobactereas (CRE) in Argentina.

METHODS

A decision tree model was developed to estimate the clinical cure (CC), survival and costs for each alternative from the payer perspective. The time horizon was the duration of the therapy. The comparators were Fosfomicin high dose/Colistin, Colistin/high dose carbapenem, Colistin/amikacin and amikacin/high dose carbapenem and Colistin/Tigecycline. The model was populated using local epidemiological data. Cure rates were based on clinical trials, published data and local expert opinion. Hospital length of stay associated with treatment cures/failures was derived from clinical trials of CAZ-AVI. Costs of drugs were obtained from ANMAT's National Drug Vademecum. Costs of hospital stay were based on tariffs from private institutions of Argentina. Each treatment option was compared with CAZ-AVI. Costs were expressed in 2020 US-dollars (exchange rate: $1=AR$69.64, July 2020). Deterministic and probabilistic sensitivity analyses assessed the robustness of results.

RESULTS

The cost-effectiveness analysis showed that in patients with multi-resistant CRE IAI the use of CAZ-AVI was a dominant treatment option at a WTP threshold of $10,006 (1 GDP/capita). In patients with K Pneumoniae IAI the estimated incremental cost-effectiveness ratio (ICER) was dominant when compared with colistin/tigecycline (ICER=-$4,353/CC), colistin/high dose carbapenem (ICER=-$4,796/CC), colistin/amikacin (ICER=-$4,508/CC) and amikacin/high dose carbapenem (ICER=-$8,058/CC) and Fosfomycin high dose/colistin (ICER=-$57,147/CC). For patients with Escherichia Coli IAI CAZ-AVI also showed to be a cost-effective alternative compared with colistin/tigecycline (ICER=-$3,237/CC), colistin/high dose carbapenem (ICER=-$4,593/CC), colistin/amikacin (ICER=-$3,127/CC) and amikacin/high dose carbapenem (ICER=-$4,545/CC) and fosfomycin high dose/colistin (ICER=-$68,283/CC). Deterministic and probabilistic sensitivity analyses show that results are robust to all scenarios.

CONCLUSIONS

The cost-effective analysis has demonstrated that CAZ-AVI appears to be a dominant treatment in patients with intraabdominal infections due to carbapenem resistant Enterobactereas in Argentina.