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Focus on sharing individual patient data distracts from other ways of improving trial transparency

BMJ 2017; 357 doi: (Published 22 June 2017) Cite this as: BMJ 2017;357:j2782
  1. Tammy Hoffmann, professor1,
  2. Paul Glasziou, professor1,
  3. Elaine Beller, associate professor1,
  4. Ben Goldacre, senior clinical research fellow2,
  5. Iain Chalmers, coordinator3
  1. 1Centre for Research in Evidence-Based Practice, Bond University, Gold Coast, Australia
  2. 2Centre for Evidence-Based Medicine, University of Oxford, Oxford, UK
  3. 3James Lind Initiative, Oxford, UK
  1. Correspondence to: T Hoffmann thoffmann{at}

The debate on sharing clinical trial data has been dominated by individual patient data. Tammy Hoffmann and colleagues argue that, although patient level data are important, a focus on the other simpler elements of trial transparency should be the first priority

The International Committee of Medical Journal Editors (ICMJE) recently reiterated its commitment to improving trial transparency by sharing individual patient data from randomised trials.1 2 But, although sharing individual patient data contributes to transparency, it is not sufficient by itself. Trial transparency requires a data sharing package, which begins with trial registration and contains other elements such as protocols, summary results, and other trial materials.

Valuable as sharing individual patient data can be,3 discussion about it has hijacked the broader conversation about data sharing and trial transparency.4 5 6 For example, we identified 76 articles published in the six leading general medical journals that had “data” and “sharing” in their title and were about clinical trials. In 64 (84%) articles, the content was focused on individual patient data and did not mention any of the other components of trial transparency (see appendix on

Much of the discussion has focused on the complexities and practical problems associated with sharing individual patient data and on the processes and systems needed for responsible data sharing.6 7 8 9 However, many of the data sharing activities that are needed for trial transparency are not complex. We believe that trying to solve the complex issues around availability of individual patient data should not eclipse or distract from a more pressing problem: the unavailability of even summary data and protocols from all controlled trials. Current estimates are that around 85% of research is avoidably “wasted” because of design flaws, poor conduct, non-publication, and poor reporting.10 Focusing efforts and attention …

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