Authors
Davidson M1, Evrenoglou T1, Graña C2, Chaimani A3, Boutron I2
1Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris
2Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris; Centre d’Epidémiologie Clinique, AP-HP, Hôpital Hôtel Dieu, F-75004, Paris; Cochrane France, Paris
3Université Paris Cité and Université Sorbonne Paris Nord, Inserm, INRAE, Center for Research in Epidemiology and Statistics (CRESS), F-75004 Paris; Cochrane France, Paris
Abstract
Background:
Preprints have emerged as a major source of research communication during the COVID-19 pandemic. However, questions were raised concerning the reliability of their results.
Objectives:
To evaluate whether effect estimates differ between preprint and peer-reviewed journal randomised controlled trials (RCTs).
Methods:
Data were derived from the COVID-NMA (covid-nma.com) initiative, a living systematic review of RCTs evaluating preventive interventions, treatments and vaccines for COVID-19. Meta-analyses with at least one preprint and one peer-reviewed journal article evaluating pharmacological treatments vs. standard of care/placebo were included up to July 20, 2022. Predefined COVID-NMA ‘critical outcomes’ at 28 days were considered. A meta-epidemiological analysis estimated the difference in effect estimates [expressed as the ratio of odds ratio (ROR)] between preprint and peer-reviewed journal RCTs. An ROR of
