title: Impact of antibiotic restriction on resistance levels of Escherichia coli: a controlled interrupted time series study of a hospital-wide antibiotic stewardship programme.
abstract: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital.
  
  
  
  The study was conducted as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels of E. coli. Results were directly compared with data from the control hospital utilizing a subtracted time series (STS).
  
  
  
  Direct comparison with the control hospital showed that the ASP was associated with a significant change in the level of use of cephalosporins [-151 DDDs/1000 bed-days (95% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)].
  
  
  
  The ASP significantly reduced the use of cephalosporins and fluoroquinolones, with concomitant decreasing levels of E. coli resistance to cefuroxime and ciprofloxacin. The same development was not observed at the control hospital.
authors.affiliation: Department of Clinical Microbiology, Herlev Hospital, University of Copenhagen, Herlev, Denmark Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark Capital Region Pharmacy, Herlev Hospital, Herlev, Denmark jonas.boel@regionh.dk.
authors.forename: Jonas
authors.initials: J
authors.lastname: Boel
authors.affiliation: Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark.
authors.forename: Viggo
authors.initials: V
authors.lastname: Andreasen
authors.affiliation: Department of Clinical Microbiology, Herlev Hospital, University of Copenhagen, Herlev, Denmark.
authors.forename: Jens Otto
authors.initials: JO
authors.lastname: Jarløv
authors.affiliation: Department of Clinical Microbiology, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Østergaard
authors.affiliation: Infectious Disease Unit, Medical Department, Herlev Hospital, University of Copenhagen, Herlev Denmark.
authors.forename: Ida
authors.initials: I
authors.lastname: Gjørup
authors.affiliation: Capital Region Pharmacy, Herlev Hospital, Herlev, Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Bøggild
authors.affiliation: Department of Clinical Microbiology, Herlev Hospital, University of Copenhagen, Herlev, Denmark.
authors.forename: Magnus
authors.initials: M
authors.lastname: Arpi
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D004363:Drug Utilization; D004926:Escherichia coli / Q000187:drug effects*; D006291:Health Policy; D006785:Hospitals, University; D006801:Humans; D065186:Interrupted Time Series Analysis; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents