Diversity of antimicrobial use and resistance in 42 hospitals in the United States.
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.
Pakyz
Amy
A
Department of Pharmacy, School of Pharmacy, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia 23298, USA.
Powell
J Patrick
JP
Harpe
Spencer E
SE
Johnson
Chris
C
Edmond
Michael
M
Polk
Ron E
RE
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
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D024841:Fluoroquinolones; D015378:Imipenem; D008712:Methicillin