Reporting of conflicts of interest from drug trials in Cochrane reviews: cross sectional studyBMJ 2012; 345 doi: https://doi.org/10.1136/bmj.e5155 (Published 20 August 2012) Cite this as: BMJ 2012;345:e5155
- Michelle Roseman, master’s student1,
- Erick H Turner, assistant professor2,
- Joel Lexchin, professor3,
- James C Coyne, professor4,
- Lisa A Bero, professor5,
- Brett D Thombs, associate professor1
- 1Lady Davis Institute for Medical Research, Jewish General Hospital and McGill University, Montreal, Quebec, Canada, H3T 1E4
- 2Department of Psychiatry, Oregon Health and Science University and Portland Veterans Affairs Medical Center, Portland, OR, USA
- 3School of Health Policy and Management, York University, Toronto, ON, Canada
- 4Department of Health Science, Health Psychology Section, University Medical Center Groningen, University of Groningen, Netherlands
- 5Department of Clinical Pharmacy, School of Pharmacy and Institute for Health Policy Studies, School of Medicine, University of California, San Francisco, USA
- Correspondence to: B D Thombs
- Accepted 12 July 2012
Objectives To investigate the degree to which Cochrane reviews of drug interventions published in 2010 reported conflicts of interest from included trials and, among reviews that reported this information, where it was located in the review documents.
Design Cross sectional study.
Data sources Cochrane Database of Systematic Reviews.
Selection criteria Systematic reviews of drug interventions published in 2010 in the Cochrane Database of Systematic Reviews, with review content classified as up to date in 2008 or later and with results from one or more randomised controlled trials.
Results Of 151 included Cochrane reviews, 46 (30%, 95% confidence interval 24% to 38%) reported information on the funding sources of included trials, including 30 (20%, 14% to 27%) that reported information on trial funding for all included trials and 16 (11%, 7% to 17%) that reported for some, but not all, trials. Only 16 of the 151 Cochrane reviews (11%, 7% to 17%) provided any information on trial author-industry financial ties or trial author-industry employment. Information on trial funding and trial author-industry ties was reported in one to seven locations within each review, with no consistent reporting location observed.
Conclusions Most Cochrane reviews of drug trials published in 2010 did not provide information on trial funding sources or trial author-industry financial ties or employment. When this information was reported, location of reporting was inconsistent across reviews.
Contributors: MR contributed to the study design, reviewed articles for inclusion, carried out the data extraction, contributed to the analysis, interpretation, and presentation of the data, and drafted the manuscript with the input of BDT and the other authors. EHT, JL, JCC, and LAB contributed to the study design and contributed a critical revision of the manuscript. BDT was responsible for the study concept and design, reviewed articles for inclusion, carried out the data extraction, contributed to the analysis, interpretation, and presentation of the data, consulted with MR on the drafting of the manuscript, and contributed a critical revision of the manuscript. He is the guarantor. All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.
Funding: MR was supported by a Frederick Banting and Charles Best Canadian graduate scholarship-master’s award from the Canadian Institutes of Health Research, a master’s training award from the Fonds de la Recherche en Santé Québec, a McGill University provost’s graduate fellowship, and a McGill University principal’s graduate fellowship. BDT was supported by a new investigator award from the Canadian Institutes of Health Research and an Établissement de Jeunes Chercheurs award from the Fonds de la Recherche en Santé Québec. This study received no funding, and no funding body had any input into any aspect of the study.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare that: no authors had any financial support for the submitted work; JL was a consultant to a law firm representing Apotex in 2007, a consultant to the Canadian federal government in a lawsuit challenging the Canadian ban on direct to consumer advertising of prescription drugs in 2007-08, and a consultant to a law firm representing a plaintiff in a case against Allergan in 2010; LAB has received a grant from the Cochrane Collaboration Methodological Fund to examine how systematic reviewers identify unpublished drug trial data, and is an active member of the Cochrane Collaboration.
Ethical approval: Not required.
Data sharing: No additional data available.
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