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Underreporting of conflicts of interest among authors of clinical drug trials: cross sectional study

Date and Location




Sunday 22 September 2013 - 10:30 - 12:00


Presenting author and contact person

Presenting author

Andreas Lundh

Contact person

Andreas Lundh
Abstract text
Background Conflicts of interest (COI) may influence how the benefits and harms of treatments are interpreted. Knowledge about individual author COI is therefore important when reading an article. However, some COI may be undisclosed by authors. Objectives To determine the prevalence of conflicts of interest among non-industry employed Danish physicians who are authors of clinical trials and determine the number of undisclosed conflicts of interest in trial publications. Methods We searched EMBASE for articles with at least one Danish author. Two assessors included the 100 most recent articles of drug trials published in international journals that adhere to the ICMJE’s manuscript guidelines. For each article, two assessors independently extracted data on trial characteristics and author COI. We determined the prevalence and type of disclosed COI among non-industry employed Danish physician authors. We compared the COI reported in the articles to those reported on the publicly available Danish Health and Medicines Authority’s disclosure list in order to identify undisclosed COI. Results A pilot study of ten articles included seven with industry sponsorship, one with mixed sponsorship and two with non-industry sponsorship. Twenty-eight (26%) out of 107 authors were non-industry employed Danish physicians. Eleven out of 28 authors disclosed one or more COI in the journal. We found that among the 28 authors 7 had undisclosed COI related to the trial sponsor or manufacturer of the drug being studied. Nine of the 28 authors had undisclosed COI related to competing companies manufacturing drugs for the same indication as the trial drug. Full data analysis of all 100 trials and further exploration of data will be presented at the conference. Conclusions Our preliminary results suggest that there is substantial underreporting of COI in clinical trials. Publicly available disclosure lists may assists journal editors in ensuring that all COI are disclosed.