Are manufacturers sharing data as promised?

BMJ 2015; 351 doi: (Published 25 September 2015) Cite this as: BMJ 2015;351:h4169
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  1. Evan Mayo-Wilson, assistant scientist, Center for Clinical Trials and Evidence Synthesis, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA,
  2. Peter Doshi, assistant professor, University of Maryland School of Pharmacy, Baltimore,
  3. Kay Dickersin, professor, Center for Clinical Trials and Evidence Synthesis, Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health
  1. evan.mayo-wilson{at}

The drug industry’s rhetoric over transparency of clinical trial data may not be reflected in practice

Over the past two years drug and device manufacturers have been among the most vocal contributors to the discussion about transparency of clinical trial data. In 2013 GlaxoSmithKline (GSK) established its Clinical Study Data Request system to share participant level data, and now 11 other companies are listed as contributors to it ( Other companies have developed similar systems of their own,1 but it is difficult to evaluate how they are working or even to decide on what basis they should be judged.

Paradoxically, despite manufacturers’ publicized support for research transparency, processes for sharing data remain opaque. In the first year of operation of the Clinical Study Data Request system an “independent review panel” reported that it shared data concerning 13 projects.2 In their declarations on the website dated November 2013, one panel member lists “none” under ”financial interests,” and another member does not list consulting fees from GSK. In their declarations related to an article about the process published in 2014, the members of this panel all reported consulting fees or indirect support from GSK (the only member who did not report personal fees is chairman of a company that has a contract with GSK), and some reported payments from other companies contributing to the site.2

At the time of writing, the Clinical Study Data Request website says that data have been provided for 58 requests, and some information is available about 64 “agreed” research proposals. The website does not explain what limitations affect the use of data for …

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