title: Medication errors: a prospective cohort study of hand-written and computerised physician order entry in the intensive care unit.
abstract: BACKGROUND
  The study aimed to compare the impact of computerised physician order entry (CPOE) without decision support with hand-written prescribing (HWP) on the frequency, type and outcome of medication errors (MEs) in the intensive care unit.
  
  
  METHODS
  Details of MEs were collected before, and at several time points after, the change from HWP to CPOE. The study was conducted in a London teaching hospital's 22-bedded general ICU. The sampling periods were 28 weeks before and 2, 10, 25 and 37 weeks after introduction of CPOE. The unit pharmacist prospectively recorded details of MEs and the total number of drugs prescribed daily during the data collection periods, during the course of his normal chart review.
  
  
  RESULTS
  The total proportion of MEs was significantly lower with CPOE (117 errors from 2429 prescriptions, 4.8%) than with HWP (69 errors from 1036 prescriptions, 6.7%) (p < 0.04). The proportion of errors reduced with time following the introduction of CPOE (p < 0.001). Two errors with CPOE led to patient harm requiring an increase in length of stay and, if administered, three prescriptions with CPOE could potentially have led to permanent harm or death. Differences in the types of error between systems were noted. There was a reduction in major/moderate patient outcomes with CPOE when non-intercepted and intercepted errors were combined (p = 0.01). The mean baseline APACHE II score did not differ significantly between the HWP and the CPOE periods (19.4 versus 20.0, respectively, p = 0.71).
  
  
  CONCLUSIONS
  Introduction of CPOE was associated with a reduction in the proportion of MEs and an improvement in the overall patient outcome score (if intercepted errors were included). Moderate and major errors, however, remain a significant concern with CPOE.
authors.affiliation: Pharmacy Department, University College London Hospitals, Middlesex Hospital, London, UK. robert.shulman@uclh.nhs.uk
authors.forename: Rob
authors.initials: R
authors.lastname: Shulman
authors.forename: Mervyn
authors.initials: M
authors.lastname: Singer
authors.forename: John
authors.initials: J
authors.lastname: Goldstone
authors.forename: Geoff
authors.initials: G
authors.lastname: Bellingan
mesh_terms: D016009:Chi-Square Distribution; D016303:Clinical Pharmacy Information Systems; D015331:Cohort Studies; D011307:Drug Prescriptions; D004360:Drug Therapy, Computer-Assisted / Q000706:statistics & numerical data*; D006236:Handwriting; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D050316:Medical Order Entry Systems / Q000706:statistics & numerical data*; D008508:Medication Errors / Q000706:statistics & numerical data*; D008510:Medication Systems, Hospital; D011446:Prospective Studies