title: Antibiotic prescribing for adults in ambulatory care in the USA, 2007-09.
abstract: OBJECTIVE
  To determine patterns of ambulatory antibiotic prescribing in US adults, including the use of broad-spectrum 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
  Antibiotics were prescribed during 101 million (95% CI: 91-111 million) ambulatory visits annually, representing 10% of all visits. Broad-spectrum agents were prescribed during 61% of visits in which antibiotics were prescribed. The most commonly prescribed antibiotics were quinolones (25% of antibiotics), macrolides (20%) and aminopenicillins (12%). Antibiotics were most commonly 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.
authors.affiliation: School of Medicine, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Shapiro
authors.forename: Lauri A
authors.initials: LA
authors.lastname: Hicks
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pavia
authors.forename: Adam L
authors.initials: AL
authors.lastname: Hersh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000379:methods*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D011307:Drug Prescriptions / Q000592:standards / Q000706:statistics & numerical data*; D004363:Drug Utilization / Q000592:standards / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: antibiotic resistance; antibiotic stewardship; prescribing patterns