title: Cost-effectiveness of an electronic medication ordering system (CPOE/CDSS) in hospitalized patients.
abstract: BACKGROUND
  Prescribing medication is an important aspect of almost all in-hospital treatment regimes. Besides their obviously beneficial effects, medicines can also cause adverse drug events (ADE), which increase morbidity, mortality and health care costs. Partially, these ADEs arise from medication errors, e.g. at the prescribing stage. ADEs caused by medication errors are preventable ADEs. Until now, medication ordering was primarily a paper-based process and consequently, it was error prone. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) is considered to enhance patient safety. Limited information is available on the balance between the health gains and the costs that need to be invested in order to achieve these positive effects. Aim of this study was to study the balance between the effects and costs of CPOE/CDSS compared to the traditional paper-based medication ordering.
  
  
  METHODS
  The economic evaluation was performed alongside a clinical study (interrupted time series design) on the effectiveness of CPOE/CDSS, including a cost minimization and a cost-effectiveness analysis. Data collection took place between 2005 and 2008. Analyses were performed from a hospital perspective. The study was performed in a general teaching hospital and a University Medical Centre on general internal medicine, gastroenterology and geriatric wards. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) was compared to a traditional paper based system. All costs of both medication ordering systems are based on resources used and time invested. Prices were expressed in Euros (price level 2009). Effectiveness outcomes were medication errors and preventable adverse drug events.
  
  
  RESULTS
  During the paper-based prescribing period 592 patients were included, and during the CPOE/CDSS period 603. Total costs of the paper-based system and CPOE/CDSS amounted to €12.37 and €14.91 per patient/day respectively. The Incremental Cost-Effectiveness Ratio (ICER) for medication errors was 3.54 and for preventable adverse drug events 322.70, indicating the extra amount (€) that has to be invested in order to prevent one medication error or one pADE.
  
  
  CONCLUSIONS
  CPOE with basic CDSS contributes to a decreased risk of preventable harm. Overall, the extra costs of CPOE/CDSS needed to prevent one ME or one pADE seem to be acceptable.
authors.affiliation: Department of Epidemiology, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands.
authors.forename: K M
authors.initials: KM
authors.lastname: Vermeulen
authors.affiliation: Department of Clinical Pharmacy and Pharmacology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: J E
authors.initials: JE
authors.lastname: van Doormaal
authors.affiliation: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: R J
authors.initials: RJ
authors.lastname: Zaal
authors.affiliation: Department of Clinical Pharmacy and Pharmacology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: P G M
authors.initials: PG
authors.lastname: Mol
authors.affiliation: Department of Clinical Pharmacy, TweeSteden Hospital and St. Elisabeth Hospital, Tilburg, The Netherlands.
authors.forename: A W
authors.initials: AW
authors.lastname: Lenderink
authors.affiliation: Department of Clinical Pharmacy and Pharmacology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: F M
authors.initials: FM
authors.lastname: Haaijer-Ruskamp
authors.affiliation: Department of Clinical Pharmacy and Pharmacology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: J G W
authors.initials: JG
authors.lastname: Kosterink
authors.affiliation: Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands. Electronic address: p.vandenbemt@erasmusmc.nl.
authors.forename: P M L A
authors.initials: PM
authors.lastname: van den Bemt
mesh_terms: D003362:Cost-Benefit Analysis; D020000:Decision Support Systems, Clinical / Q000191:economics*; D064420:Drug-Related Side Effects and Adverse Reactions / Q000517:prevention & control*; D006760:Hospitalization / Q000191:economics*; D006784:Hospitals, Teaching; D006801:Humans; D050316:Medical Order Entry Systems / Q000191:economics* / Q000592:standards / Q000706:statistics & numerical data; D008508:Medication Errors / Q000517:prevention & control*; D058996:Quality Improvement
keywords: Computerized decision support system; Computerized physician order entry; Cost-effectiveness