1885. Cost-Effectiveness of Ceftazidime–Avibactam Compared With Colistin for Treatment of Carbapenem-Resistant Enterobacteriaceae Bacteremia and Pneumonia

BACKGROUND: Ceftazidime/avibactam (CAZ/AVI) may improve outcomes among patients with carbapenem-resistant Enterobacteriaceae (CRE) infections. However, the cost-effectiveness of CAZ/AVI is unknown. METHODS: We used a decision analytic model to estimate the health and economic consequences of CAZ/AVI-based therapy compared with colistin-based therapy (COL) for a hypothetical cohort of patients with CRE pneumonia and bacteremia over a 1-year time horizon. Model inputs were from published sources and included CRE mortality with COL (41%), CAZ/AVI’s absolute risk reduction (ARR) in CRE mortality (23%), daily cost of CAZ/AVI ($1,080), risk of NTX with COL (42%), probability of discharge to long-term care (LTC) following CRE infection (56%), and improved odds of discharge home with CAZ/AVI compared with COL (1.8). Outcomes included quality adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICER; $/QALY). 1-way and probabilistic sensitivity analyses were performed and ICERs were compared with willingness to pay standards of $100,000/QALY and $150,000/QALY. RESULTS: The ICER for CAZ/AVI compared with COL was $110,300/QALY (table). In 1-way sensitivity analyses, CAZ/AVI had an ICER <$100,000/QALY when the ARR in CRE mortality was >29%, the odds of discharge home with CAZ/AVI was > 1.9, CAZ/AVI’s daily cost was <$775, quality of life weight following discharge home was >0.92, risk of NTX with COL was >49% or annual costs of LTC were <$75,890. CAZ/AVI had an ICER >$150,000/QALY when CAZ/AVI’s ARR in CRE mortality was <12%, the odds of discharge home with CAZ/AVI compared with COL was <1.3, or the quality of life weight following discharge home was <0.61. In probabilistic sensitivity analysis, CAZ/AVI was the optimal strategy in 40% and 76% of simulations at willingness to pay thresholds of $100,000/QALY and $150,000/QALY, respectively (figure). [Image: see text] CONCLUSION: CAZ/AVI is appropriate from an economic perspective based on efficacy data from observational studies and willingness to pay standards in the United States. DISCLOSURES: M. Satlin, Allergan: Grant Investigator, Research grant.