Adverse events, healthcare interventions and healthcare utilization during home infusion therapy with daptomycin and vancomycin: a propensity score-matched cohort study.

OBJECTIVES Vancomycin and daptomycin are the two most frequently prescribed parenteral antimicrobials for resistant Gram-positive bacterial infections. The purpose of this study was to compare antimicrobial adverse event rates and associated healthcare interventions and healthcare utilization in patients treated with the two antimicrobials. METHODS All patients aged ≥18 years, discharged home from Cleveland Clinic on outpatient parenteral antimicrobial therapy (OPAT) with daptomycin or vancomycin between 1 July 2007 and 30 June 2010 were screened. Logistic regression models were built to calculate propensity to be treated with daptomycin for each patient. Propensity score-matched vancomycin-treated controls were identified for each daptomycin-treated patient. Adverse event, healthcare intervention and healthcare utilization rates during OPAT were compared in the matched cohort using negative binomial regression models. RESULTS One thousand, two hundred and eighty-eight patients were identified. Three-to-one matching provided the best matching characteristics and identified 119 daptomycin-treated subjects (2518 OPAT days) and 357 vancomycin-treated controls (6649 OPAT days). The mean patient age was 56 years and the mean OPAT duration was 19 days. Antimicrobial adverse event rates for the daptomycin and vancomycin groups were 3.2 and 7.7 per 1000 OPAT days, respectively [relative risk (RR) 0.38; 95% CI 0.15-0.86; P = 0.02]. Antimicrobial intervention rates were 5.6 and 27.1 per 1000 OPAT days, respectively (RR 0.21; 95% CI 0.11-0.36; P < 0.001). Readmissions for worsening infection or treatment complication were not significantly different between daptomycin (5%) and vancomycin (7%). CONCLUSIONS Patients receiving daptomycin at home have 60% fewer antimicrobial adverse events and require 80% fewer antimicrobial interventions than similar patients receiving vancomycin.