Conflicts of interest in peer review of biomedical research

While conflicts of interest among authors of biomedical manuscripts have received much attention, little is known about conflicts of interest among peer reviewers. The Committee on Publication Ethics’ ‘Ethical guidelines for peer reviewers’ describe how reviewers should disclose relevant conflicts of interest in order to provide a fair and unbiased review (Cope Council 2017). However, a survey of medical journal editors by Cooper and colleagues found that only 42 of 91 editors (46%) reported that the journal had a specific conflict of interest policy for peer reviewers (2006). Regrettably the authors did not undertake an actual analysis of the content of conflicts of interest polices or investigate how editors manage peer reviewers’ conflicts of interest in practice. Furthermore, we are unaware of any studies reporting on the prevalence of conflicts of interest among peer reviewers. One older experimental study by Mahoney on fictitious manuscripts in behavioural psychology found that reviewers were more critical and more often recommended rejection when results in manuscripts contradicted the reviewer’s theoretical perspective (1977). Similarly, a qualitative study on grant reviews by Abdoul and colleagues found that one-third of grant applicants reported personal experience with peer reviewers’ non-financial conflicts of interest in the application process (2012). While both studies suggest that non-financial conflicts of interest may influence peer reviewer recommendations, we are unaware of any empirical studies investigating the influence of conflicts of interest on the content of reviewer reports of actual manuscripts submitted to biomedical journals. How biomedical journals address and manage peer reviewers’ conflicts of interest, how frequent such conflicts are and whether they have influence on the content of reviewer reports therefore remains unknown. Our project consists of four studies with the overall aim of investigating conflicts of interest in peer review of biomedical research.

Peer review is important to ensure the quality of scientific research. However, there is a risk that the assessor's personal opinions and conflicts of interest may influence the actual assessment of the article and thus what studies and results are published.

Both financial conflicts of interest and non-financial conflicts of interest may have an impact. Financial conflicts of interest may arise when the assessor cooperates financially with a company whose medicinal product is part of the trial they are required to assess. Non-financial conflicts of interest can occur when the assessor belongs to a particular professional group that prefers a specific treatment, for example, when psychiatrists or psychologists have to judge a trial of antidepressants against psychotherapy.

Numerous scientific studies have shown that researchers with conflicts of interest more often draw positive conclusions in their articles compared to researchers without conflicts of interest. However, conflicts of interest among peer reviewers have been sparsely investigated.

In four studies, we will examine how health science journals handle peer reviewers' conflicts of interest, how frequent conflicts of interest occur among peer reviewers, and whether their conflicts of interest are associated with the assessment of the articles. The results of the studies can eventually lead to better guidelines in the journals, thus increasing the quality of the scientific papers and ensuring a fair assessment.