title: The influence that electronic prescribing has on medication errors and preventable adverse drug events: an interrupted time-series study.
abstract: OBJECTIVE
  This study evaluated the effect of a Computerized Physician Order Entry system with basic Clinical Decision Support (CPOE/CDSS) on the incidence of medication errors (MEs) and preventable adverse drug events (pADEs).
  
  
  METHODS
  Interrupted time-series design.
  
  
  METHODS
  The primary outcome measurements comprised the percentage of medication orders with one or more MEs and the percentage of patients with one or more pADEs.
  
  
  RESULTS
  Pre-implementation, the mean percentage of medication orders containing at least one ME was 55%, whereas this became 17% post-implementation. The introduction of CPOE/CDSS has led to a significant immediate absolute reduction of 40.3% (95% CI: -45.13%; -35.48%) in medication orders with one or more errors. Pre-implementation, the mean percentage of admitted patients experiencing at least one pADE was 15.5%, as opposed to 7.3% post-implementation. However, this decrease could not be attributed to the introduction of CPOE/CDSS: taking into consideration the interrupted time-series design, the immediate change was not significant (-0.42%, 95% CI: -15.52%; 14.68%) because of the observed underlying negative trend during the pre-CPOE period of -4.04% [95% CI: -7.70%; -0.38%] per month.
  
  
  CONCLUSIONS
  This study has shown that CPOE/CDSS reduces the incidence of medication errors. However, a direct effect on actual patient harm (pADEs) was not demonstrated.
authors.affiliation: Department of Hospital and Clinical Pharmacy, University Medical Center Groningen, P.O. Box 30,001, 9,700 RB Groningen, The Netherlands. j.e.van.doormaal@apoth.umcg.nl
authors.forename: Jasperien E
authors.initials: JE
authors.lastname: van Doormaal
authors.forename: Patricia M L A
authors.initials: PM
authors.lastname: van den Bemt
authors.forename: Rianne J
authors.initials: RJ
authors.lastname: Zaal
authors.forename: Antoine C G
authors.initials: AC
authors.lastname: Egberts
authors.forename: Bertil W
authors.initials: BW
authors.lastname: Lenderink
authors.forename: Jos G W
authors.initials: JG
authors.lastname: Kosterink
authors.forename: Flora M
authors.initials: FM
authors.lastname: Haaijer-Ruskamp
authors.forename: Peter G M
authors.initials: PG
authors.lastname: Mol
mesh_terms: D000368:Aged; D055695:Electronic Prescribing; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008508:Medication Errors / Q000517:prevention & control*; D008875:Middle Aged; D009426:Netherlands; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies