Unreviewed science in the news: The evolution of preprint media coverage from 2014-2021

It has been argued that preprint coverage during the COVID-19 pandemic constituted a paradigm shift in journalism norms and practices. This study examines whether and in what ways this is the case using a sample of 11,538 preprints posted on four preprint servers-bioRxiv, medRxiv, arXiv, and SSRN-that received coverage in 94 English-language media outlets between 2014 and 2021. We compared mentions of these preprints with mentions of a comparison sample of 397,446 peer-reviewed research articles indexed in the Web of Science to identify changes in the share of media coverage that mentioned preprints before and during the pandemic. We found that preprint media coverage increased at a slow but steady rate prepandemic, then spiked dramatically. This increase applied only to COVID-19-related preprints, with minimal change in coverage of preprints on other topics. The rise in preprint coverage was most pronounced among health and medicine-focused media outlets, which barely covered preprints before the pandemic but mentioned more COVID-19 preprints than outlets focused on any other topic. These results suggest that the growth in coverage of preprints seen during the pandemic may imply only a temporary shift in journalistic norms, including a changing outlook on reporting preliminary, unvetted research.