title: Trends in aminoglycoside use and gentamicin-resistant gram-negative clinical isolates in US academic medical centers: implications for antimicrobial stewardship.
abstract: OBJECTIVE
  To measure trends in aminoglycoside antibiotic use and gentamicin-resistant clinical isolates across a network of hospitals and compare network-level relationships with those of individual hospitals.
  
  
  METHODS
  Longitudinal observational investigation.
  
  
  METHODS
  US academic medical centers.
  
  
  METHODS
  Adult inpatients.
  
  
  METHODS
  Adult aminoglycoside use was measured from 2002 or 2003 through 2009 in 29 hospitals. Hospital-wide antibiograms assessed gentamicin resistance by proportions and incidence rates for Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli. Mixed-effects analysis of variance was used to assess the significance of changes in aminoglycoside use and changes in resistance rates and proportions. Generalized estimating equations were used to assess the relationship between aminoglycoside use and resistance.
  
  
  RESULTS
  Mean aminoglycoside use declined by 41%, reflecting reduced gentamicin (P < .0001) and tobramycin (P < .005) use; amikacin use did not change. The rate and proportion of gentamicin-resistant P. aeruginosa decreased by 48% (P < .0001) and 31% (P < .0001), respectively. The rate and proportion of gentamicin-resistant E. coli increased by 166% and 124%, respectively (P < .0001), and they were related to increasing quinolone resistance in E. coli. Resistance among K. pneumoniae and A. baumannii did not change. Relationships between aminoglycoside use and resistance at the network level were highly variable at the individual hospital level.
  
  
  CONCLUSIONS
  Mean aminoglycoside use declined in this network of US hospitals and was associated with significant and opposite changes in rates of resistance for some organisms and no change for others. At the individual hospital level, antibiograms appear to be an unreliable reflection of antibiotic use, at least for aminoglycosides.
authors.affiliation: Department of Pharmacotherapy and Outcome Science, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Mera
authors.initials: M
authors.lastname: Ababneh
authors.forename: Spencer
authors.initials: S
authors.lastname: Harpe
authors.forename: Michael
authors.initials: M
authors.lastname: Oinonen
authors.forename: Ron E
authors.initials: RE
authors.lastname: Polk
mesh_terms: D000046:Academic Medical Centers / Q000639:trends*; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000302:isolation & purification; D000328:Adult; D000617:Aminoglycosides / Q000494:pharmacology; D000704:Analysis of Variance; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016208:Databases, Factual; D024881:Drug Resistance, Bacterial; D004363:Drug Utilization / Q000639:trends*; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000302:isolation & purification; D008137:Longitudinal Studies; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D014481:United States
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D005839:Gentamicins