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Research Methods & Reporting

CONSORT Harms 2022 statement, explanation, and elaboration: updated guideline for the reporting of harms in randomised trials

BMJ 2023; 381 doi: (Published 24 April 2023) Cite this as: BMJ 2023;381:e073725

Linked Opinion

Future directions of research into harms in randomised controlled trials

  1. Daniela R Junqueira, research associate1,
  2. Liliane Zorzela, assistant clinical professor1,
  3. Susan Golder, associate professor2,
  4. Yoon Loke, senior lecturer3,
  5. Joel J Gagnier, associate professor4,
  6. Steven A Julious, professor5,
  7. Tianjing Li, associate professor6 7,
  8. Evan Mayo-Wilson, associate professor8,
  9. Ba Pham, research coordinator9,
  10. Rachel Phillips, senior lecturer10,
  11. Pasqualina Santaguida, assistant professor11,
  12. Roberta W Scherer, retired senior scientist12,
  13. Peter C Gøtzsche, director13,
  14. David Moher, senior scientist14 15,
  15. John P A Ioannidis, professor16,
  16. Sunita Vohra, professor1
  17. on behalf of the CONSORT Harms Group
    1. 1Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
    2. 2Department of Health Sciences, University of York, York, UK
    3. 3Norwich Medical School, University of East Anglia, Norwich, UK
    4. 4Department of Epidemiology and Biostatistics, Department of Surgery, Western University, London, ON, Canada
    5. 5Design, Trials and Statistics, School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
    6. 6Department of Ophthalmology, School of Medicine, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
    7. 7Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
    8. 8Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC, USA
    9. 9Knowledge Translation Programme, Unity Health Toronto, Toronto, ON, Canada
    10. 10Faculty of Medicine, School of Public Health, Imperial College London, London, UK
    11. 11Department of Health Research Methods, Evidence and Impact (HEI), McMaster University, Hamilton, ON, Canada
    12. 12Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
    13. 13Institute for Scientific Freedom, Hørsholm, Denmark
    14. 14Centre for Journalology, Clinical Epidemiology Programme, Ottawa Hospital Research Institute, Ottawa, ON, Canada
    15. 15School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
    16. 16Departments of Medicine, of Epidemiology and Population Health, of Biomedical Data Science, and of Statistics, Stanford University, Stanford, CA, USA
    1. Correspondence to: S Vohra svohra{at}
    • Accepted 6 February 2023

    Randomised controlled trials remain the reference standard for healthcare research on effects of interventions, and the need to report both benefits and harms is essential. The Consolidated Standards of Reporting Trials (the main CONSORT) statement includes one item on reporting harms (ie, all important harms or unintended effects in each group). In 2004, the CONSORT group developed the CONSORT Harms extension; however, it has not been consistently applied and needs to be updated. Here, we describe CONSORT Harms 2022, which replaces the CONSORT Harms 2004 checklist, and shows how CONSORT Harms 2022 items could be incorporated into the main CONSORT checklist. Thirteen items from the main CONSORT were modified to improve harms reporting. Three new items were added. In this article, we describe CONSORT Harms 2022 and how it was integrated into the main CONSORT checklist, and elaborate on each item relevant to complete reporting of harms in randomised controlled trials. Until future work from the CONSORT group produces an updated checklist, authors, journal reviewers, and editors of randomised controlled trials should use the integrated checklist presented in this paper.

    Randomised controlled trials are the reference standard among study designs to investigate the benefits of interventions. These trials are the foundation for regulatory approval of drugs and are also important when evaluating surgical procedures, medical devices, psychological and behavioural interventions, social interventions, and complementary therapies. Ideally, randomised controlled trials should evaluate not only potential benefits of interventions, but also potential harms. However, these trials are often limited in their ability to evaluate harms because of the short duration of intervention and follow-up, restricted study populations (eg, excluding participants with comorbidities or receiving cointerventions), and lack of statistical power to assess rare events.1234 Nevertheless, prospectively collected data about harms in randomised controlled trials are important to inform …

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