Evaluating Twitter as a complementary data source for pharmacovigilance

ABSTRACTBackground: Social media are currently considered as a potential complementary source of knowledge for drug safety surveillance. Our primary objective was to estimate the frequency of adverse drug reactions(ADRs) experienced by Twitter users. Our secondary objective was to determine whether tweets constitute a valuable and informative source of data for pharmacovigilancepurposes, despite limitations on character number per tweet.Research design and methods: We selected a list of 33 drugs subject to careful monitoring due to safety concern in France and Europe, and extracted tweets using the streaming API from 30 September 2014 to 5 April 2015. Two pharmacovigilancecenters classified these tweets manually as potential ADR case reports.Results: Among 10,534 tweets, 848 (8.05%) implied or mentioned an ADR without meeting the four FDA criteria required for reporting an ADR, and 289 (2.74%) tweets were classified as ‘case reports.’ Among them 20 (7.27%) tweets mentioned an unexpected ADR and 33 (11....