title: The impact of a computerized physician order entry system on medical errors with antineoplastic drugs 5 years after its implementation.
abstract: OBJECTIVE
  Computerized physician order entry (CPOE) systems reduce medical errors (MEs). Nevertheless, a CPOE system may also lead to new types of errors, especially when it is first implemented. The objectives of this study were to determine the impact of a CPOE on the number of MEs and to identify the types of MEs in prescriptions issued by the Haematology Department 5 years after the implementation of the CPOE system.
  
  
  METHODS
  We conducted a prospective analytical study on the implementation of a CPOE system at the Pharmacy Department of the Hospital Ramon y Cajal (Madrid, Spain). The study comprised three phases: a pre-implementation phase, an implementation phase conducted in the Haematology Department and a post-implementation phase, which was conducted 5 years after the implementation of the CPOE system. One hundred and fifty prescriptions per pre- and post-implementation phase were consecutively included in the study. A previously described classification scheme was used to detect and classify MEs.
  
  
  CONCLUSIONS
  The implementation of a CPOE system was associated with a large reduction in MEs. One hundred and fourteen patients (pre-implementation phase) were compared to 82 patients (post-implementation phase). The total number of MEs per 100 patients decreased from 236·8 (95% CI: 212·1-261·3) to 10·9 (95% CI: 5·8-19·6), with an absolute risk reduction of 36·2 (95% CI: 32·6-39·9). The percentage of prescriptions with an ME decreased from 37·5% to 1·2% (P < 0.001). In the pre-implementation phase, the drugs most frequently associated with MEs were rituximab (35·9%), cyclophosphamide (13%) and methotrexate (7%). In the post-implementation phase, 44·4% of prescription errors involved methotrexate. Five years after the implementation of the CPOE system, the majority of MEs were eliminated, the number of remaining errors (quantity, concentration and ambiguous prescription errors) decreased, and no new types of ME were detected.
  
  
  CONCLUSIONS
  The CPOE system almost completely eliminated MEs with antineoplastic drugs in the Haematology Department. No new types of MEs were observed once physicians had become accustomed to using the system. However, some MEs were not eliminated. Constant diligence is needed to analyse and evaluate MEs associated with the CPOE system and their causes, such that the limitations of CPOE can be identified and overcome and the medication-use process associated with antineoplastic agents improved.
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Sanchez Cuervo
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Rojo Sanchis
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Pueyo Lopez
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Gomez de Salazar Lopez de Silanes
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Gramage Caro
authors.affiliation: Department of Pharmacy, Ramon y Cajal Hospital, Madrid, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Bermejo Vicedo
keywords: drug utilisation; intravenous infusions; pharmacy practice; prescribing practices; validation