Pharmacoeconomic Analysis to Compare Dalbavancin and Vancomycin in an Outpatient Parenteral Antimicrobial Therapy (OPAT) Population

Background: Despite its many challenges, vancomycin is the most commonly prescribed antimicrobial in the OPAT population for treatment of infections caused by gram positive, drug resistant pathogens, including methicillin-resistant Staphylococcus aureus. Dalbavancin has fewer drug therapy management challenges in the outpatient setting, but comes with a significantly higher acquisition cost. The objective of this study was to determine if the use of dalbavancin in the UR Medicine OPAT population may result in lower overall costs, despite higher acquisition costs.

Methods: All patients who received intravenous (IV) vancomycin through UR Medicine’s OPAT program from 3/1/11 to 6/30/14 were included.  Medical records were reviewed to capture demographic information and adverse events.  Hospital billing data were obtained to determine treatment costs. The overall cost for treatment with vancomycin for each patient was compared to a calculated predicted cost for dalbavancin assuming appropriate monitoring and a similar length of treatment as vancomycin therapy. Sensitivity analysis to determine the impact of estimations including variations in cost and other monitoring parameters were performed.

Results: After exclusions, 142 patients were included. The most common indications were osteomyelitis, skin and soft tissue infection, and bacteremia. Ninety-seven patients (68%) completed therapy as prescribed, 9 patients (6%) completed therapy with a complication, and 37 patients (26%) did not finish. The most common causes of treatment failures were readmission due to worsening infection (n=15) and complication of IV therapy (n=15). With an acquisition cost of $7.22/gram, the total drug cost of vancomycin was $63,565. With an acquisition cost of $1490/0.5 gram vial, the projected drug cost of dalbavancin was $1,208,390.

Conclusion: This study is expected to aid institutions in determining the appropriate place in therapy of dalbavancin. While the projected drug cost for dalbavancin was higher than the total drug cost of vancomycin, the potential benefits to patients go far beyond drug acquisition costs. This analysis used data from patients treated through an existing OPAT program to give a real-world view of potential overall costs of dalbavancin.