title: Development of a computer algorithm for defining an active drug list using an automated pharmacy database.
abstract: OBJECTIVE
  Increasingly, pharmacy databases are being used to assist in evaluating the appropriateness of drug therapy. Such determinations often require the creation of a drug regimen at a particular point in time. The objective of this study was to develop a computer algorithm for defining a cross-sectional active drug list.
  
  
  METHODS
  Electronic pharmacy data were obtained as part of the Iowa Medicaid Pharmaceutical Case Management Program. The active drug lists generated by the computer algorithm were compared with active drug lists generated by independent pharmacist review of the pharmacy refill data.
  
  
  RESULTS
  In a sample of 25 patients who received 379 potentially active medications, the interrater reliability between pharmacist reviewers was excellent (kappa=0.94). In a second sample of 100 patients who received 1476 potentially active medications, the computer algorithm had a sensitivity of 93.8% and specificity of 91.7%, using pharmacist review as the comparison standard.
  
  
  CONCLUSIONS
  The computer algorithm was found to be a valid method of processing electronic pharmacy data to yield a characterization of drug exposure at a point in time. The potential benefits and limitations of using this approach are discussed.
authors.affiliation: Laureate Psychiatric Research Center, Laureate Psychiatric Clinics and Hospital, 6655 South Yale Avenue, Tulsa, OK 74136, USA. bclund@saintfrancis.com
authors.forename: Brian C
authors.initials: BC
authors.lastname: Lund
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Chrischilles
authors.forename: Barry L
authors.initials: BL
authors.lastname: Carter
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ernst
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Perry
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016208:Databases, Factual; D017723:Drug Utilization Review; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017891:Pharmacoepidemiology; D012680:Sensitivity and Specificity