Conflicts of interest can affect our ability to remain open-minded and may lead to a subconscious urge to reciprocate the kind gestures and donations of a funder. Furthermore, they can draw attention away from what is in the patients’ best interest and instead serve the doctors’ or researchers’ other interests.

The overall aim of this PhD was to examine conflicts of interest in scientific articles within the medical field. This was done in three separate studies. In our first study, we assessed what general medical journal and specialty journal authors’ positions were relating to one of three versions of an independent and comprehensive Cochrane systematic review on mammography screening, whether there were geographical differences, and whether acceptance of the review had changed over time. In our second study we examined the prevalence of conflicts of interest among Danish doctors who were authors on clinical randomised controlled trials and determined the extent of under-reporting of conflicts of interest. Finally, in our third study, we determined the involvement of academic authors of industry-funded clinical randomised controlled trials in the design, conduct, data analysis and reporting. Furthermore, we assessed what their experiences were with industry collaboration.

In our first study, we found that authors of publications in general medical journals were more accepting of and less likely to reject the results and methods of the systematic Cochrane review of mammography screening compared to authors of publications in specialty journals. We found no geographical differences, but there was a tendency towards greater acceptance of the systematic review over time.

In our second study, we found that one in three Danish doctors who were authors on  clinical drug trial publications had declared financial conflicts of interest with a pharmaceutical industry company. We also found that one in eight doctors failed to declare financial conflicts of interest with the industry funder of the trial and that conflicts of interest with other pharmaceutical companies often remained undeclared.

In our third study, we found that academic authors on industry-funded clinical trials mostly collaborated with industry employees on the trial design, conduct and reporting, but the data analysis was most often conducted by industry statisticians. Most lead academic authors reported that the collaboration was beneficial and access to funding, publications in high-impact journals and prestige were among important benefits reported. However, some authors reported disagreements with the industry funder typically concerning trial design or reporting.

Authors of publications in general medical journals showed greater acceptance of the results and methods in the systematic review on mammography screening compared to authors from specialty journals. The difference in acceptance could be related to specialty journal authors’ affiliation and conflicts of interest.

Self-declared conflicts of interest statements in trial publications are often unreliable. Public registries of doctors’ collaboration with pharmaceutical industry companies can help achieve a more comprehensive declaration of conflicts of interest.

Industry-funded trials were often designed, conducted, analysed and reported with funder influence. While many of the lead academic authors found the collaboration with industry beneficial, some authors reported loss of academic freedom.

Academic Supervisor

Peter C. Gøtzsche, Professor, Dr Med., Director of Nordic Cochrane Centre, Rigshospitalet, Denmark.

Co-supervisors

Andreas Lundh, PhD, MSc, MD Center for Evidence-Based Medicine

Odense University Hospital and University of Southern Denmark, Department of Infectious Diseases, Hvidovre Hospital, Denmark.

Karsten J Jørgensen, Dr Med., Deputy Director of Nordic Cochrane Centre, Rigshospitalet, Denmark

Chair

Marjukka Mäkelä, MD, PhD, MSc, Professor of General Practice, University of Copenhagen, Denmark, Professor Emerita, National Institute for Health and Welfare, Finland.

Christopher Baethge, Professor, Dr Med., University of Cologne Medical School, Germany. Chief Scientific Editor of of Deutsches Ärzteblatt.

Ana Marusic, Professor, University of Split School of Medicine, Croatia and Honorary Professor University of Edinburgh, UK. Co-editor in Chief of the Journal of Global Health.