title: Timing of publication of abstracts of randomized controlled trials presented in congresses: The example of the European League against Rheumatism meeting.
abstract: The EUropean League Against Rheumatism (EULAR) congress is an important meeting to present abstracts of research in rheumatology. However, information in these abstracts is insufficient and must be followed and developed in a published article. This study aims to assess to what extent abstracts presented in the EULAR Meeting are published in journals.
  
  
  
  We identified all abstracts of randomized controlled trials accepted for presentation at the EULAR annual meeting from 2002 to 2011. Using a standardized research, we used Pubmed to find the corresponding publication to each congress abstract. We assessed the cumulative percentage of published abstracts over time and compared the number of included patients, the outcome and the moment of outcome assessment between abstracts presented in congress and in published article.
  
  
  
  A total of 1839 abstracts were analyzed. The cumulative probability of abstracts being published in journals was 16.9% (95% CI: 15.2% to 18.6%) at 12 months, 34.3% (95% CI: 32.2% to 36.5%) at 24 months, and 46.5% (95% CI: 44.2% to 48.8%) at 36 months. When evaluable, a difference between the congress and published abstracts was found in 29.0% (247/852). The most frequent difference was a different number of included patients (196/247: 79.4%).
  
  
  
  More than half of the abstracts of randomized trials were not published three years after they were presented in EULAR meeting. Thirty percent of abstracts were different between their presented and published version.
authors.affiliation: Clermont 1 University, Rheumatology Department, Gabriel-Montpied Teaching Hospital, 63000 Clermont-Ferrand, France. Electronic address: smathieu@chu-clermontferrand.fr.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Mathieu
authors.affiliation: Centre d'Épidémiologie Clinique, Hôpital Hôtel-Dieu, Assistance publique-Hôpitaux de Paris, 75004 Paris, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Baron
authors.affiliation: Clermont 1 University, Rheumatology Department, Gabriel-Montpied Teaching Hospital, 63000 Clermont-Ferrand, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Soubrier
authors.affiliation: Centre d'Épidémiologie Clinique, Hôpital Hôtel-Dieu, Assistance publique-Hôpitaux de Paris, 75004 Paris, France; Paris Descartes University, 75006 Paris, France; Inserm, UMR 1153 Centre of Research in Epidemiology and Statistics Sorbonne Paris Cité (CRESS), METHODS team, 75005 Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ravaud
keywords: Congress abstract; EULAR; Timing of publication