title: Diversity of antimicrobial use and resistance in 42 hospitals in the United States.
abstract: OBJECTIVE
  To measure diversity (or heterogeneity) of antibiotic use in a sample of hospitals in the United States and to assess an association with bacterial resistance.
  
  
  METHODS
  Observational cross-sectional study.
  
  
  METHODS
  Forty-two general medical-surgical hospitals, mostly in the Eastern United States.
  
  
  METHODS
  Administrative claims data and hospital antibiograms during 2003.
  
  
  RESULTS
  Antibiotic use was measured by defined daily dose (DDD), and diversity was assessed by using Simpson's Index and the Shannon-Weiner Index. Aggregated antibiograms (from 17 hospitals) were used to assess resistance. There were a total of 3,655,579 patient-days during 2003, with a mean +/- SD of 87,037 +/- 62,679 patient-days/hospital. Mean +/- SD antibiotic use was 704 +/- 244 DDD/1000 patient-days/hospital, and fluoroquinolones represented the largest single class. Mean +/- SD diversity by Simpson's Index was 0.861 +/- 0.022/hospital, and a strong correlation was noted between the two diversity measures. Multivariate analysis found no significant relationship between diversity and the proportion of resistant pathogens.
  
  
  CONCLUSIONS
  Diversity of aggregate antibiotic use can be measured, but additional investigations are needed to determine if it is a useful strategy to contain resistance.
authors.affiliation: Department of Pharmacy, School of Pharmacy, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia 23298, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Pakyz
authors.forename: J Patrick
authors.initials: JP
authors.lastname: Powell
authors.forename: Spencer E
authors.initials: SE
authors.lastname: Harpe
authors.forename: Chris
authors.initials: C
authors.lastname: Johnson
authors.forename: Michael
authors.initials: M
authors.lastname: Edmond
authors.forename: Ron E
authors.initials: RE
authors.lastname: Polk
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002511:Cephalosporins; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D017723:Drug Utilization Review; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D015378:Imipenem / Q000008:administration & dosage / Q000627:therapeutic use; D008712:Methicillin / Q000008:administration & dosage / Q000627:therapeutic use; D015999:Multivariate Analysis; D014481:United States
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D024841:Fluoroquinolones; D015378:Imipenem; D008712:Methicillin