Slightly more than half of COVID-19–related scientific studies posted on the preprint server medRxiv were published in peer-reviewed journals within the next 2 years, according to a research letter published yesterday in JAMA Network Open.
In March 2022, researchers in Denmark, Spain, and Austria searched for all COVID-19 preprints (non–peer-reviewed papers) posted on medRxiv from Jan 1 to Dec 31, 2020. The team repeated the search in October 2022.
Of the 3,343 preprints, 1,712 (51.2%) were published in the peer-reviewed literature (579 journals) by March 2022. By October 2022, this number had risen to 1,742 (52.1%). Excluding January 2020, when only one COVID-19 article was posted, the rate of later publication in a journal ranged from 43.5% (94 of 216 preprints posted in March 2020) to 60.6% (177 of 292 preprints posted in August 2020).
Of the 1,712 preprints later published in journals, 827 (47.5%) were published in quartile 1 (top-quality) journals such as PLOS One, Scientific Reports, and BMJ Open.
The researchers noted that, since medRxiv's 2019 launch, the dissemination of research as preprints has grown rapidly, largely fueled by the COVID-19 pandemic. "Notwithstanding, this unprecedented increase in preprints has been subject to criticism, mainly because of reliability concerns owing to their lack of peer review," they wrote.
The steady rate of publication in peer-reviewed journals over the course of the study suggests that a substantial change in the proportion of medRxiv studies later published in the literature is unlikely, the authors said. "Future studies aimed at evaluating publication rates in other areas of medical science are needed," they wrote.