Antibiotic prescribing for adults in ambulatory care in the USA, 2007-09

Abstract

Objectives: To determine patterns of ambulatory antibiotic prescribing in US adults, including the use of broadspectrum versus narrow-spectrum agents, to provide a description of the diagnoses for which antibiotics are prescribed and to identify patient and physician factors associated with broad-spectrum antibiotic prescribing. Methods:We used data for patients aged ≥18 years from the National Ambulatory and National Hospital Ambulatory Medical Care Surveys (2007-09). These are nationally representative surveys of patient visits to offices, hospital outpatient departments and emergency departments (EDs) in the USA, collectively referred to as ambulatory visits. We determined the types of antibiotics prescribed, including the use of broad-spectrum versus narrow-spectrum antibiotics, and examined prescribing patterns by diagnoses. We used multivariable logistic regression to identify factors associated with broad-spectrum antibiotic prescribing. Results: Antibioticswere prescribed during 101 million (95% CI: 91-111 million) ambulatory visits annually, representing10% of all visits. Broad-spectrum agentswere prescribed during61%of visits in which antibioticswere prescribed. The most commonly prescribed antibiotics were quinolones (25% of antibiotics), macrolides (20%) and aminopenicillins (12%). Antibioticswere mostcommonly prescribed for respiratory conditions(41% of antibiotics), skin/mucosal conditions (18%) and urinary tract infections (9%). In multivariable analysis, among patients prescribed antibiotics, broad-spectrum agents were more likely to be prescribed than narrow-spectrum antibiotics for respiratory infections for which antibiotics are rarely indicated (e.g. bronchitis), during visits to EDs and for patients ≥60 years. Conclusions: Broad-spectrum agents constitute the majority of antibiotics in ambulatory care. More than 25% of prescriptions are for conditions for which antibiotics are rarely indicated. Antibiotic stewardship interventions targeting respiratory and non-respiratory conditions are needed in ambulatory care. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.