title: Algorithms used in adverse drug event reports: a comparative study.
abstract: OBJECTIVE
  To determine if and how the Kramer and Karch algorithms differ in assigning a probability that a published case was actually an adverse drug event (ADE), and to determine if these algorithms could be used to assess published ADEs.
  
  
  METHODS
  Open, single-rater comparison of Karch and Kramer algorithms in 200 published ADE reports.
  
  
  RESULTS
  The algorithms were not significantly different regarding the proportion of cases deemed definite (p = 0.5204) or probable (p = 0.2972) ADEs. The Kramer instrument was more likely to assign a possible risk of ADE (p = 0.0001), while the Karch instrument was more likely to assign a risk of unlikely (p = 0.0001). The algorithms agreed in 41% of the cases and could be used to assess published ADEs.
  
  
  CONCLUSIONS
  The Karch and Kramer algorithms may disagree in how they assign a probability of risk to a potential ADE. This may be due to how algorithms are applied, as well as to structural differences.
authors.affiliation: School of Pharmacy, University of Washington, Seattle, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Frick
authors.forename: L G
authors.initials: LG
authors.lastname: Cohen
authors.forename: J P
authors.initials: JP
authors.lastname: Rovers
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000465:Algorithms; D016009:Chi-Square Distribution; D003657:Decision Making; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D011336:Probability; D012306:Risk