Cost-effectiveness of ceftazidime-avibactam for treatment of carbapenem-resistant Enterobacteriaceae bacteremia and pneumonia

Ceftazidime-avibactam (CAZ-AVI) may improve outcomes among patients with carbapenem-resistant Enterobacteriaceae (CRE) infections compared to those with conventional therapies. However, CAZ-AVI's cost-effectiveness is unknown. We used a decision analytic model to estimate the health and economic consequences of CAZ-AVI-based therapy compared to colistin-based therapy (COL) for a hypothetical cohort of patients with CRE pneumonia or bacteremia over a 5-year horizon. Model inputs were from published sources and included CRE mortality with COL (41%), CAZ-AVI's absolute risk reduction in CRE mortality (23%), daily cost of CAZ-AVI ($926), risk of nephrotoxicity with COL (42%), and probability of discharge to long-term care (LTC) following CRE infection (56%). Outcomes included quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICER; dollars/QALY). One-way and probabilistic sensitivity analyses were performed and ICERs were compared to willingness-to-pay standards of $100,000/QALY and $150,000/QALY. In the base case, CAZ-AVI had an ICER of $95,000/QALY. At a $100,000/QALY threshold, results were sensitive to a number of variables, including the probability and cost of LTC, quality of life following CRE infection, CAZ-AVI's absolute risk reduction in mortality, all-cause mortality, daily cost of CAZ-AVI, and health care costs after CRE infection. The ICER did not exceed $150,000/QALY after all model inputs were varied across a wide range of plausible values. In probabilistic sensitivity analysis, CAZ-AVI was the optimal strategy in 59% and 99% of simulations at $100,000/QALY and $150,000/QALY thresholds, respectively. In conclusion, CAZ-AVI is a cost-effective treatment for CRE bacteremia and pneumonia based on accepted willingness to pay standards in the United States.