OBJECTIVES: The incidence of infection with antibiotic-resistant bacteria is steadily increasing in the world, and the treatment of drug-resistant bacterial infection has become a challenge. Complicated urinary tract infections (CUTIs) are problematic conditions frequently encountered by physicians. The primary objective of this study was to evaluate the incremental cost-effectiveness of ceftazidime/avibactam (CAZ-AVI) compared to other antibiotics in the treatment of adult patients with complicated urinary tract infection (cUTI), including pyelonephritis in Bulgaria.

METHODS: A sequential, individual-level simulation model was developed in Microsoft Excel to simulate the costs and effectiveness of treatment in patients with complicated infections. The model was populated with epidemiologic local data and conducted a patient-level therapy simulation (Monte Carlo simulation). For the Bulgarian base case, the key comparators were imipenem/cilastatin, levofloxacin and piperacillin/tazobactam. Costs were calculated according to the positive drug list (PDL) as of July 2018. Both costs and health outcomes were estimated for a time horizon of 5 years and were discounted at an annual rate of 5% using TreeAge Pro Software.

RESULTS: The cost-effectiveness analysis revealed that in patients with cUTI, including pyelonephritis, the use of CAZ-AVI was a cost-effective treatment option at a WTP threshold of 37 000 BGN in comparison with imipenem/cilastatin (ICER = BGN 13,172.63 BGN/QALY); levofloxacin (ICER = 28,680.63 BGN/QALY) and piperacillin/tazobactam (ICER = 22,481.66 BGN/ QALY).

CONCLUSIONS: From the payer perspective (hospital), CAZ-AVI is a cost-effective option in the treatment of cUTI and with its effectiveness against many drug-resistant, gram-negative bacteria and its unique action against carbapenemases, is seemingly an appropriate choice for the treatment of life-threatening infections.