title: Unintended medication discrepancies associated with reliance on prescription databases for medication reconciliation on admission to a general medical ward.
abstract: BACKGROUND
  In a recent study, 50% of the patients who were admitted to a hospital's general medicine ward had at least one error in medication orders at the time of admission related to inaccuracies in the medication history. The use of computerized prescription databases has been suggested as a way to improve medication reconciliation at the time of admission.
  
  
  OBJECTIVE
  To quantify and describe unintended discrepancies between a best possible medication history and medications ordered on admission to the general medicine ward in a hospital with routine access to a provincial outpatient prescription database (British Columbia's PharmaNet).
  
  
  METHODS
  This prospective study involved 20 patients who were regularly using at least 4 prescription medications before admission to hospital. The best possible medication history for each patient (based on a review of the medical chart and the PharmaNet record and an interview with the patient) was compared with the physician's admission orders to identify any discrepancies. The frequency and perceived severity of discrepancies, graded independently by 3 physicians, were compared with observations from a similar study conducted at a hospital where a prescription database was not available.
  
  
  RESULTS
  The 20 patients were recruited between September 2005 and January 2006. For 8 patients (40%), information in the PharmaNet database was consistent with the prescription medication list obtained during the best possible medication history at the time of admission. For the other 12 patients, a total of 30 unintended discrepancies were identified, 13 (43%) of which were classified as having potential for moderate or severe harm. The proportion of patients with unintended discrepancies was similar to that for the comparison cohort (60% versus 54%). Although the percentage of discrepancies involving omissions was lower than in the comparison population (37% versus 46%), these results were offset by a higher proportion of commission discrepancies (27% versus 0%).
  
  
  CONCLUSIONS
  Unintended discrepancies were frequent, despite use of the PharmaNet database at the time of admission. Inconsistencies between the PharmaNet record and patients' actual medication use, coupled with failure to verify PharmaNet data with patients, were likely contributing factors.
authors.affiliation: , BSc(Pharm), ACPR, was, at the time of writing, a pharmacy resident, and is now a staff editor for  Martindale, the Complete Drug Reference  at the Royal Pharmaceutical Society of Great Britain, London, England.
authors.forename: Kelli
authors.initials: K
authors.lastname: Kalb
authors.forename: Stephen
authors.initials: S
authors.lastname: Shalansky
authors.forename: Michael
authors.initials: M
authors.lastname: Legal
authors.forename: Nadia
authors.initials: N
authors.lastname: Khan
authors.forename: Irene
authors.initials: I
authors.lastname: Ma
authors.forename: Garth
authors.initials: G
authors.lastname: Hunte