Comparative Effectiveness of Beta-lactams versus Vancomycin for Treatment of Methicillin-Susceptible Staphylococcus aureus Bloodstream Infections among 122 Hospitals.
Clin Infect Dis. 2015 Apr 21;
Authors: McDanel JS, Perencevich EN, Diekema DJ, Herwaldt LA, Smith TC, Chrischilles EA, Dawson JD, Jiang L, Goto M, Schweizer ML
Abstract
BACKGROUND: Previous studies indicated that vancomycin is inferior to beta-lactams for treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections. However, it is unclear if this association is true for both empiric and definitive therapy. This study compared beta-lactams with vancomycin for empiric and definitive therapy of MSSA bloodstream infections among patients admitted to 122 hospitals.
METHODS: This retrospective cohort study included all patients admitted to Veteran's Affairs hospitals from 2003 to 2010 who had positive blood cultures for MSSA. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression. Empiric therapy was defined as starting treatment 2 days before until 4 days after the first MSSA blood culture was collected. Definitive therapy was defined as starting treatment between 4 to 14 days after the first positive blood culture was collected.
RESULTS: Patients who received empiric therapy with a beta-lactam had similar mortality compared with vancomycin (HR: 1.03; 95% CI: 0.89-1.20) after adjusting for other factors. However, patients who received definitive therapy with a beta-lactam had 35% lower mortality compared with patients receiving vancomycin (HR: 0.65; CI: 0.52-0.80) after controlling for other factors. The hazard of mortality decreased further for patients who received cefazolin or an antistaphylococcal penicillin compared with vancomycin (HR: 0.57; CI: 0.46-0.71).
CONCLUSIONS: For patients with MSSA bloodstream infections, beta-lactams are superior to vancomycin for definitive therapy but not for empiric treatment. Patients should receive a beta-lactam for definitive therapy, specifically an antistaphylococcal penicillin or cefazolin.
PMID: 25900170 [PubMed - as supplied by publisher]