OBJECTIVES: To assess whether oritavancin and dalbavancin are cost-effective alternatives to vancomycin in treating Infective Endocarditis (IE) caused by Methicillin-resistant Staphylococcus aureus (MRSA) in Persons Who Inject Drugs (PWID).

METHODS: This is a retrospective, decision and cost-effectiveness analysis. We constructed a decision-analytic model considering three alternative treatment strategies: vancomycin, dalbavancin, and oritavancin. We performed base-case and sensitivity analyses. Outcome measures included costs in 2019 US dollars, and life expectancy based on Social Security Auctorial Life Expectancy Table and the rate of treatment success, hospital re-admissions, and death. We obtained data estimates from fifteen published articles through March 2020. Studies included 644 PWID out of 1412 IE patients. We incorporated the short-term disutility from hospitalization by assuming those days were worth only 0.90 of a healthy day. Costs for medications and hospitalization were retrieved from the Federal Supply Schedule and Centers for Medicare Services payment tables. We used Decision Maker 2.2 (Boston, MA) software to build and analyze the model.

RESULTS: Oritavancin was the most effective and least expensive alternative yielding effectiveness a life expectancy of 26.7 years and a cost of $93,332. Dalbavancin was the second most preferred treatment yielding a life expectancy of 26.4 years at a lifetime cost of $94,584. Vancomycin was the most expensive and least effective with a cost of $256,670 and a life expectancy of 25.5 years. Our results were robust and stable across numerous one-way sensitivity analyses.

CONCLUSIONS: Dalbavancin and oritavancin are cost-effective alternatives to vancomycin for the treatment of IE caused by MRSA in PWID. Future studies are needed to evaluate the feasibility and effectiveness of these new alternatives on the PWID population.