Comparing quality of reporting between preprints and peer-reviewed articles in the biomedical literature

ABSTRACT

Preprint usage is growing rapidly in the life sciences; however, questions remain on the relative quality of preprints when compared to published articles. An objective dimension of quality that is readily measurable is completeness of reporting, as transparency can improve the reader's ability to independently interpret data and reproduce findings. In this observational study, we compared random samples of articles published in bioRxiv and in PubMed-indexed journals in 2016 using a quality of reporting questionnaire. We found that peer-reviewed articles had, on average, higher quality of reporting than preprints, although this difference was small. We found larger differences favoring PubMed in subjective ratings of how clearly titles and abstracts presented the main findings and how easy it was to locate relevant reporting information. Interestingly, an exploratory analysis showed that preprints with figures and legends embedded within text had reporting scores similar to PubMed articles. These differences cannot be directly attributed to peer review or editorial processes, as manuscripts might already differ before submission due to greater uptake of preprints by particular research communities. Nevertheless, our results show that quality of reporting in preprints in the life sciences is within a similar range as that of peer-reviewed articles, albeit slightly lower on average, supporting the idea that preprints should be considered valid scientific contributions. An ongoing second phase of the project is comparing preprints to their own published versions in order to more directly assess the effects of peer review. / FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro)