Intended for healthcare professionals

Research Methods & Reporting

Improving the reporting of pragmatic trials: an extension of the CONSORT statement

BMJ 2008; 337 doi: (Published 11 November 2008) Cite this as: BMJ 2008;337:a2390
  1. Merrick Zwarenstein, director123,
  2. Shaun Treweek, senior research fellow45,
  3. Joel J Gagnier, post-graduate fellow56,
  4. Douglas G Altman, director7,
  5. Sean Tunis, director8910,
  6. Brian Haynes, Michael Gent professor and chair11,
  7. Andrew D Oxman, senior researcher5,
  8. David Moher, senior scientist1213
  9. for the CONSORT and Pragmatic Trials in Healthcare (Practihc) groups
  1. 1Health Services Sciences, Sunnybrook Hospital, Toronto, Ontario, Canada
  2. 2Institute for Clinical Evaluative Sciences, Toronto Department of Health Policy, Management and Evaluation, University of Toronto, Toronto
  3. 3Division of International Health (IHCAR), Karolinska Institute, Stockholm, Sweden
  4. 4Clinical and Population Sciences and Education, University of Dundee, Dundee
  5. 5Norwegian Knowledge Centre for the Health Services, Oslo, Norway
  6. 6Faculty of Medicine, University of Toronto
  7. 7Centre for Statistics in Medicine, University of Oxford, Oxford
  8. 8Center for Medical Technology Policy, Baltimore, MD, USA
  9. 9Division of General Internal Medicine, Johns Hopkins School of Medicine, Baltimore, MD
  10. 10Center for Healthcare Policy, Stanford University School of Medicine, Palo Alto, CA, USA
  11. 11Department of Clinical Epidemiology and Biostatistics and Department of Medicine, McMaster University Faculty of Health Sciences, Hamilton, ON, Canada
  12. 12Clinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Canada
  13. 13Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa
  1. Correspondence to: M Zwarenstein merrick.zwarenstein{at}
  • Accepted 2 October 2008

Background The CONSORT statement is intended to improve reporting of randomised controlled trials and focuses on minimising the risk of bias (internal validity). The applicability of a trial’s results (generalisability or external validity) is also important, particularly for pragmatic trials. A pragmatic trial (a term first used in 1967 by Schwartz and Lellouch) can be broadly defined as a randomised controlled trial whose purpose is to inform decisions about practice. This extension of the CONSORT statement is intended to improve the reporting of such trials and focuses on applicability.

Methods At two, two-day meetings held in Toronto in 2005 and 2008, we reviewed the CONSORT statement and its extensions, the literature on pragmatic trials and applicability, and our experiences in conducting pragmatic trials.

Recommendations We recommend extending eight CONSORT checklist items for reporting of pragmatic trials: the background, participants, interventions, outcomes, sample size, blinding, participant flow, and generalisability of the findings. These extensions are presented, along with illustrative examples of reporting, and an explanation of each extension. Adherence to these reporting criteria will make it easier for decision makers to judge how applicable the results of randomised controlled trials are to their own conditions. Empirical studies are needed to ascertain the usefulness and comprehensiveness of these CONSORT checklist item extensions. In the meantime we recommend that those who support, conduct, and report pragmatic trials should use this extension of the CONSORT statement to facilitate the use of trial results in decisions about health care.

Pragmatic trials are designed to inform decisions about practice, but poor reporting can reduce their usefulness. The CONSORT and Practihc groups describe modifications to the CONSORT guidelines to help readers assess the applicability of the results


  • We thank Eduardo Bergel, Curt Furberg, Jeremy Grimshaw, Jan Hux, Andreas Laupacis, John Lavis, Simon Lewin, Carl Lombard, Malcolm Maclure, Dale Needham, Dave Sackett, Kevin Thorpe, and the Practihc and CONSORT groups for their contributions.

  • Funding: The Practihc group was supported by the European Commission’s 5th Framework INCO programme, contract ICA4-CT-2001-10019. The 2005 Toronto meeting was supported by the Canadian Institutes for Health Research grant number FRN 63095. The 2008 Toronto meeting was supported by the UK Medical Research Council, the Centre for Health Services Sciences at Sunnybrook Hospital, Toronto, Canada, the Centre for Medical Technology Policy, Balitimore, Maryland, USA and the National Institute for Health and Clinical Excellence, UK. DM is supported by a University of Ottawa research chair; much of his contribution to this paper was while he was with the Children’s Hospital of Eastern Ontario Research Institute. DA is supported by Cancer Research UK.

  • Competing interests: None declared.

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

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