Objectives
During the COVID-19 pandemic, pre-prints were widely used to accelerate data dissemination. Advantages of using such material in a crisis are compelling but should still be balanced against potential limitations (e.g., the lack of peer-review and possible unexplained data discrepancies between pre-prints and corresponding journal publications). We aimed to assess recently published pre-prints on non-COVID-19 treatments, for insights into the utility of such material in the absence of related peer-reviewed publications.
Methods
The pre-print databases SSRN and MedRXiv were systematically searched for records posted in 2021 and reporting randomised trials of any pharmacological or surgical interventions for non-COVID-19 indications. MEDLINE and Embase were also searched for corresponding peer-reviewed articles published by May 2022. Data gathered and analysed included posting/publication date, sample size and any differences in definition/reporting of primary outcomes between pre-pint and peer-reviewed publication.
Results
Overall, 41 (of 688 screened) pre-prints were included, with 22 having a corresponding peer-reviewed publication. The median time from pre-print posting to journal publication was 4.35 months (range: 1–13.4 months), over a median follow-up (i.e., time from pre-print posting to database search) of 9.9 months (range: 1.8–15.5 months). For the 19 pre-prints without a peer-reviewed publication, the median follow-up was 7.4 months (range: 4.6–14.9 months). There were no discrepancies in the reporting of primary outcomes in 18 out of the 19 pre-print/peer-reviewed-publication dyads. In one of the dyads, the pre-print reported only the per-protocol results, while the peer-reviewed publication reported only the intention-to-treat analysis. Nevertheless, the overall conclusions were similar in both publications.
Conclusions
Our study suggests that pre-prints can be a reliable source of evidence, often accessible several months before any corresponding peer-reviewed publication. While the findings need confirmation in further research, they raise questions about whether pre-prints should be considered routinely in settings where early availability of data may be crucial, such as reimbursement decision-making.