title: Detection of dechallenge in spontaneous reporting systems: a comparison of Bayes methods.
abstract: OBJECTIVE
  Dechallenge is a response observed for the reduction or disappearance of adverse drug reactions (ADR) on withdrawal of a drug from a patient. Currently available algorithms to detect dechallenge have limitations. Hence, there is a need to compare available new methods. To detect dechallenge in Spontaneous Reporting Systems, data-mining algorithms like Naive Bayes and Improved Naive Bayes were applied for comparing the performance of the algorithms in terms of accuracy and error. Analyzing the factors of dechallenge like outcome and disease category will help medical practitioners and pharmaceutical industries to determine the reasons for dechallenge in order to take essential steps toward drug safety.
  
  
  METHODS
  Adverse drug reactions of the year 2011 and 2012 were downloaded from the United States Food and Drug Administration's database.
  
  
  RESULTS
  The outcome of classification algorithms showed that Improved Naive Bayes algorithm outperformed Naive Bayes with accuracy of 90.11% and error of 9.8% in detecting the dechallenge.
  
  
  CONCLUSIONS
  Detecting dechallenge for unknown samples are essential for proper prescription. To overcome the issues exposed by Naive Bayes algorithm, Improved Naive Bayes algorithm can be used to detect dechallenge in terms of higher accuracy and minimal error.
authors.affiliation: Department of Information Technology, Velammal College of Engineering and Technology, Madurai, Tamil Nadu, India.
authors.forename: A Bazila
authors.initials: AB
authors.lastname: Banu
authors.affiliation: Department of Information Technology, K.L.N College of Information Technology, Madurai, Tamil Nadu, India.
authors.forename: S Appavu
authors.initials: SA
authors.lastname: Alias Balamurugan
authors.affiliation: Department of Medicine, Chennai Medical, College Hospital and Research Centre, Irungatur, Trichy, Tamil Nadu, India.
authors.forename: Ponniah
authors.initials: P
authors.lastname: Thirumalaikolundusubramanian
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000465:Algorithms; D001499:Bayes Theorem; D057225:Data Mining; D064420:Drug-Related Side Effects and Adverse Reactions / Q000209:etiology; D006801:Humans; D060735:Pharmacovigilance
keywords: Adverse drug reaction; World Health Organisation; food and drug administration; improved naive bayes; medical dictionary for regulatory activities; naive bayes; preferred terms; system organ class