Usefulness of antibiogram surveillance for methicillin-resistant Staphylococcus aureus in outpatient pediatric populations.

We assessed the impact of distributing an outpatient age-specific methicillin-resistant Staphylococcus aureus (MRSA) antibiogram on physician knowledge of MRSA prevalence and choice of empiric therapy. Questionnaires were given to 125 physicians at outpatient pediatric clinics in Monroe County, NY, before and after antibiogram distribution (response rates, 42% and 24%, respectively). The median physician-estimated MRSA prevalence (among S. aureus skin infections) was 15% before they received the antibiogram and 20% after. According to the antibiogram, the true 2005 prevalence was 25% among skin infections. When asked to select empiric therapy for a pediatric outpatient with a skin abscess, while assuming varying levels of MRSA prevalence, most selected cephalexin when the prevalence was assumed to be 20% or less, and trimethoprim-sulfamethoxazole when the prevalence was assumed to be 30% or greater. These data suggest that antibiograms may improve empiric therapy decision making by increasing knowledge of local outpatient prevalence of antibiotic resistance.