title: A prospective analysis of the preventability of adverse drug reactions reported in Sweden.
abstract: OBJECTIVE
  Adverse drug reactions (ADRs) are a major patient safety issue, and a substantial proportion of ADRs are, in fact, preventable. The aim of this study was to describe the proportion and pattern of preventable ADRs in spontaneously reported suspected ADRs and to study the feasibility of using data from an ADR reporting system for this purpose.
  
  
  METHODS
  All reports of ADRs, except those in which a vaccine was the suspected drug, submitted to the regional pharmacovigilance center of southeastern Sweden between 2008 and 2009 were analyzed. Causality between the suspected ADR and the medication was assessed using the World Health Organization (WHO) criteria, and preventability was assessed using Hallas criteria.
  
  
  RESULTS
  During the study period, 1,290 ADRs were received and 1,255 were classified as having at least a possible causality between a reaction and a drug. Of these, 172 (14%) ADRs were considered preventable, 35 (20%) were classified as definitely preventable, and 137 (80%) as possibly preventable. Of all preventable ADRs, 96 (56%) were related to prescribing, 35 (20%) to administration, and 41 (24%) to clinical and laboratory monitoring of treatment. Warfarin, oxycodone, and ioversol were the most common drugs with preventable ADRs.
  
  
  CONCLUSIONS
  This study found that a substantial part of reported ADRs are preventable. Most of these are related to drug prescription, suggesting that interventions aiming to reduce preventable ADRs should focus on this process. Moreover, systems for ADR reporting may be useful in the mission of reducing the unsafe use of drugs.
authors.affiliation: Regional Pharmacovigilance Centre, Department of Clinical Pharmacology, Linköping University Hospital, 581 85 Linköping, Sweden. henrik.lovborg@lio.se
authors.forename: Henrik
authors.initials: H
authors.lastname: Lövborg
authors.forename: Linda Ring
authors.initials: LR
authors.lastname: Eriksson
authors.forename: Anna K
authors.initials: AK
authors.lastname: Jönsson
authors.forename: Thomas
authors.initials: T
authors.lastname: Bradley
authors.forename: Staffan
authors.initials: S
authors.lastname: Hägg
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D011307:Drug Prescriptions; D064420:Drug-Related Side Effects and Adverse Reactions / Q000139:chemically induced / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061214:Patient Safety; D060735:Pharmacovigilance; D011446:Prospective Studies; D013548:Sweden