OBJECTIVES: To estimate cost-effectiveness of Ceftazidime-Avibactam (CAZ-AVI) compared versus colistin-meropenem in the treatment of infections due to carbapenem-resistant enterobacteriaceae (CRE) in Colombia.

METHODS: A decision tree model was developed to estimate quality adjusted life-years (QALY) and costs for each alternative, from a healthcare system perspective, assuming a 30 days horizon and estimate long-term effectiveness with 5% of discounting. Inputs derived from an observational study published, modeled the base-case patient based on the cohort composition reported in this study, included CRE mortality, hospital length of stay, renal failure as an adverse event and dosing schedule. The clinical course was simulated based on treatment response between 48-72 hours and the duration of the treatment was 7-14 days. The clinical failure was defined as add on other antibiotic. The study considered that combination therapy colistin-meropenem was not superior to monotherapy based on randomized clinical trials. Cost inputs were extracted from published Colombian manual tariffs and official database, expressed in 2018 dollars (USD). The used exchanged rate was COP$2,957 per dollar. Utility values were from published literature. Both deterministic and probabilistic sensitivity analyses were performed.

RESULTS: In the base case analysis, CAZ-AVI was associated with reduction hospital length of stay and less add-on antibiotic which resulted in an increase of 1.28 QALYs per patient versus colistin-meropenem. The total costs associated to treatment with CAZ-AVI was USD$3,026 higher per patient compared to colistin-meropenem (USD$8.570 versus USD$5.544). The incremental costs were partially increased due to the low rate mortality observed in CAZ-AVI patients. The incremental cost-effectiveness ratio was estimated to USD$2.357 per QALY. In probabilistic sensitivity analysis, with a willingness to pay above USD$1,522, less than one Colombian GDP, CAZ-AVI has a higher probability of be cost-effective.

CONCLUSIONS: CAZ-AVI demonstrates to reduce the cases of deaths and increase QALYs resulting a cost-effective treatment for CRE infections.