Objectives: During the COVID-19 pandemic, BMJ, the premier journal on evidence-based medicine worldwide, published many views by advocates of specific COVID-19 policies. We aimed to evaluate the presence and potential bias of this advocacy. Design and Methods: Scopus was searched for items published until April 13, 2024 on "COVID-19 OR SARS-CoV-2". BMJ publication numbers and types before (2016-2019) and during (2020-2023) the pandemic were compared for a group of advocates favoring aggressive measures (leaders of both the Independent Scientific Advisory Group for Emergencies (indieSAGE) and the Vaccines-Plus initiative) and four control groups: leading members of the governmental Scientific Advisory Group for Emergencies (SAGE), UK-based key signatories of the Great Barrington Declaration (GBD) (favoring more restricted measures), highly-cited UK scientists, and UK scientists who published the highest number of COVID-19-related papers in the entire scientific literature (n=16 in each group). Results: 122 authors published more than 5 COVID-19-related items each in BMJ. Of those, 18 were leading members/signatories of aggressive measures advocacy groups publishing 231 COVID-19 related BMJ documents, 53 were editors/journalists, and 51 scientists were not identified as associated with any advocacy. Of 41 authors with >10 publications in BMJ, 8 were scientists advocating for aggressive measures, 7 were editors, 23 were journalists, and only 3 were non-advocate scientists. Some aggressive measures advocates already had strong BMJ presence pre-pandemic. During pandemic years, the studied indieSAGE/Vaccines-Plus advocates outperformed in BMJ presence leading SAGE members by 16.0-fold, UK-based GBD advocates by 64.2-fold, the most-cited scientists by 16.0-fold, and the authors who published most COVID-19 papers overall by 10.7-fold. The difference was driven mainly by short opinion pieces and analyses. Conclusions: BMJ appears to have favored and massively promoted specific COVID-19 advocacy views during the pandemic, thereby strongly biasing the scientific picture on COVID-19.

According to Scopus, JPAI has published 75 items over the last 30 years in the BMJ (categorized by Scopus as Articles (n=43), Reviews (n=12), Letters (n=10), Editorials (n=7) and Short Surveys (n=3) and is thus ranked 160th among the most-prolific authors in BMJ. Of the 75 items, 3 are related to COVID-19: a non-commissioned opinion piece where he has declared his opposition to signing petitions, memoranda, declarations, and any other open advocacy letters as a means to settle scientific matters; a debate article on lockdowns; and an editorial on the peer review congress co-sponsored by BMJ and his center (METRICS). IAC has published 2 Articles in BMJ and TM has published one Review in BMJ, all unrelated to COVID-19. All authors have had COVID-19-related submitted papers to BMJ rejected in ways that violated COPE ethical principles (e.g. unethical comments by advocate reviewers, decision reached but not communicated to the authors, decision signed by person not previously listed in the BMJ website as an editor, decision delayed inappropriately for time-sensitive papers). According to Scopus (all publications considered), JPAI has published 102 COVID-19-related items, TM has published 10, IAC has published 8, and KPK has published 10 COVID-19-related items.

This study did not receive any funding.

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All data used in this study are publicly available at BMJ or can be obtained via SCOPUS. We provide relevant raw data in Supplementary information. If any data or calculations remain unclear, readers are warmly welcome to contact the authors.