1. Abstract
A potential motivation for scientists to deposit their scientific work as preprints is to enhance its citation or social impact, an effect which has been empirically observed for preprints in physics, astronomy and mathematics deposited to arXiv. In this study we assessed the citation and altmetric advantage of bioRxiv, a preprint server for the biological sciences. We retrieved metadata of all bioRxiv preprints deposited between November 2013 and December 2017, and matched them to articles that were subsequently published in peer-reviewed journals. Citation data from Scopus and altmetric data from Altmetric.com were used to compare citation and online sharing behaviour of bioRxiv preprints, their related journal articles, and non-deposited articles published in the same journals. We found that bioRxiv-deposited journal articles received a sizeable citation and altmetric advantage over non-deposited articles. Regression analysis reveals that this advantage is not explained by multiple explanatory variables related to the article and its authorship. bioRxiv preprints themselves are being directly cited in journal articles, regardless of whether the preprint has been subsequently published in a journal. bioRxiv preprints are also shared widely on Twitter and in blogs, but remain relatively scarce in mainstream media and Wikipedia articles, in comparison to peer-reviewed journal articles.
