Article Text

Original research
Status, use and impact of sharing individual participant data from clinical trials: a scoping review
  1. Christian Ohmann1,
  2. David Moher2,
  3. Maximilian Siebert3,
  4. Edith Motschall4,
  5. Florian Naudet5
  1. 1European Clinical Research Infrastructure Network, Paris, France
  2. 2Ottawa Methods Centre, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
  3. 3CHU Rennes, CIC 1414 (Centre d'Investigation Clinique de Rennes), University Rennes, Rennes, France
  4. 4Institute of Medical Biometry and Statistics, Faculty of Medicine and Medical Center – University of Freiburg, Freiburg, Baden-Württemberg, Germany
  5. 5CHU Rennes, INSERM CIC 1414 (Centre d'Investigation Clinique de Rennes), University Rennes, Rennes, Bretagne, France
  1. Correspondence to Professor Christian Ohmann; christianohmann{at}


Objectives To explore the impact of data-sharing initiatives on the intent to share data, on actual data sharing, on the use of shared data and on research output and impact of shared data.

Eligibility criteria All studies investigating data-sharing practices for individual participant data (IPD) from clinical trials.

Sources of evidence We searched the Medline database, the Cochrane Library, the Science Citation Index Expanded and the Social Sciences Citation Index via Web of Science, and preprints and proceedings of the International Congress on Peer Review and Scientific Publication. In addition, we inspected major clinical trial data-sharing platforms, contacted major journals/publishers, editorial groups and some funders.

Charting methods Two reviewers independently extracted information on methods and results from resources identified using a standardised questionnaire. A map of the extracted data was constructed and accompanied by a narrative summary for each outcome domain.

Results 93 studies identified in the literature search (published between 2001 and 2020, median: 2018) and 5 from additional information sources were included in the scoping review. Most studies were descriptive and focused on early phases of the data-sharing process. While the willingness to share IPD from clinical trials is extremely high, actual data-sharing rates are suboptimal. A survey of journal data suggests poor to moderate enforcement of the policies by publishers. Metrics provided by platforms suggest that a large majority of data remains unrequested. When requested, the purpose of the reuse is more often secondary analyses and meta-analyses, rarely re-analyses. Finally, studies focused on the real impact of data-sharing were rare and used surrogates such as citation metrics.

Conclusions There is currently a gap in the evidence base for the impact of IPD sharing, which entails uncertainties in the implementation of current data-sharing policies. High level evidence is needed to assess whether the value of medical research increases with data-sharing practices.

  • health informatics
  • information management
  • information technology

Data availability statement

Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as online supplemental information. There is a link to the code and the data on the OSF (

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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Data availability statement

Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as online supplemental information. There is a link to the code and the data on the OSF (

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  • Twitter @dmoher, @Florian Naudet @NaudetFlorian

  • Contributors CO, DM and FN developed the study protocol. The search strategy was developed and implemented by EM. The selection of sources of evidence and the assessment was performed by CO and FN. Contact with initiatives/platforms/journals/publishers was performed by MS. In case of disagreements, these were resolved by consensus and, when necessary, in consultation with DM. The first draft of the manuscript was written by CO and FN. All authors have revised and approved the final manuscript.

  • Funding FN's work on data sharing is supported by a grant from the French National Research Agency-ANR (Reproducibility in Therapeutic Research/ReITheR: Agence Nationale de la Recherche, ANR-17-CE36-0010-01). CO's work on data sharing is supported by funding from the European Union’s Horizon 2020 Research and Innovation Programme (CORBEL, under grant agreement no 654248). DM is supported by an Ottawa University Research Chair (grant number: N/A).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.