[The relevance and fate of abstracts presented in scientific meetings]

Abstracts presented in scientific meetings are indispensable tools to diffuse the latest research in the field. They provide the authors with an opportunity to receive feedback from a critical audience so they can prepare a final manuscript to be submitted to a peer-reviewed journal. However, several studies in a wide range of medical specialties and other related sciences showed that no more than 50% of abstracts presented in annual meetings of learned societies are published in a 5-year follow up after the meeting. Therefore, abstracts are considered "preliminary publications" and it is recommended not to include them as bibliographic references unless they have been published recently (less than 3 years) in peer-reviewed journals (regular issues or supplements) or in their official websites. Databases dependent on the National Library of Medicine (USA) or SciELO do not index individual abstracts from a meeting. Authors and reviewers should be reminded that manuscripts that have shaped current knowledge probably had also been presented as abstracts in scientific meetings, sometime before their final publication.