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Research Methods & Reporting

PRISMA harms checklist: improving harms reporting in systematic reviews

BMJ 2016; 352 doi: (Published 01 February 2016) Cite this as: BMJ 2016;352:i157

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  1. Liliane Zorzela, clinical assistant professor1,
  2. Yoon K Loke, professor2,
  3. John P Ioannidis, professor3,
  4. Su Golder, research fellow4,
  5. Pasqualina Santaguida, assistant professor5,
  6. Douglas G Altman, professor6,
  7. David Moher, senior scientist7,
  8. Sunita Vohra, professor1,
  9. PRISMA harms group
  1. 1Department of Pediatrics, Faculty of Medicine and Dentistry, and Integrative Health Institute, University of Alberta, Edmonton, T6G 2C8, AB, Canada
  2. 2Norwich Medical School, Norwich, UK
  3. 3Stanford University School of Medicine, Stanford University School of Humanities and Sciences, Stanford, CA, USA
  4. 4Department of Health Sciences, University of York, Heslington, UK
  5. 5Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
  6. 6Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
  7. 7Ottawa Methods Centre, Ottawa Hospital Research Institute, Ottawa Hospital, Ottawa, ON, Canada
  1. Correspondence to: S Vohra svohra{at}
  • Accepted 11 December 2015


Introduction For any health intervention, accurate knowledge of both benefits and harms is needed. Systematic reviews often compound poor reporting of harms in primary studies by failing to report harms or doing so inadequately. While the PRISMA statement (Preferred Reporting Items for Systematic reviews and Meta-Analyses) helps systematic review authors ensure complete and transparent reporting, it is focused mainly on efficacy. Thus, a PRISMA harms checklist has been developed to improve harms reporting in systematic reviews, promoting a more balanced assessment of benefits and harms.

Methods A development strategy, endorsed by the EQUATOR Network and existing reporting guidelines (including the PRISMA statement, PRISMA for abstracts, and PRISMA for protocols), was used. After the development of a draft checklist of items, a modified Delphi process was initiated. The Delphi consisted of three rounds of electronic feedback followed by an in-person meeting.

Results The PRISMA harms checklist contains four essential reporting elements to be added to the original PRISMA statement to improve harms reporting in reviews. These are reported in the title (“Specifically mention ‘harms’ or other related terms, or the harm of interest in the review”), synthesis of results (“Specify how zero events were handled, if relevant”), study characteristics (“Define each harm addressed, how it was ascertained (eg, patient report, active search), and over what time period”), and synthesis of results (“Describe any assessment of possible causality”). Additional guidance regarding existing PRISMA items was developed to demonstrate relevance when synthesising information about harms.

Conclusion The PRISMA harms checklist identifies a minimal set of items to be reported when reviewing adverse events. This guideline extension is intended to improve harms reporting in systematic reviews, whether harms are a primary or secondary outcome.


  • PRISMA harms steering committee: Sunita Vohra (Convenor) (University of Alberta), David Moher (Ottawa Hospital Research Institute; University of Ottawa), Doug Altman (University of Oxford), Yoon Loke (University of East Anglia), John Ioannidis (Stanford University), Pasqualina Santaguida (McMaster University), Su Golder (University of York), Liliane Zorzela (University of Alberta). All authors participated in the development of this guideline, collaborating in the draft of the manuscript and approved the submitted version.

  • PRISMA harms group (collaborators): Heather Boon (University of Toronto), Jocalyn Clark (University of Toronto, at time of work on PRISMA harms senior editor, PLOS Medicine), Sheena Derry (University of Oxford), Jim Gallivan (Health Canada), Paula Gardiner (Boston University School of Medicine), Peter Gøtzsche (Nordic Cochrane Center), Elizabeth Loder (acting head of research, The BMJ), Maryann Napoli (Center for Medical Consumers), Karen Pilkington (University of Westminster), Paul Shekelle (Veterans Affairs Greater Los Angeles Health Care System), Sonal Singh (Johns Hopkins University School of Medicine), Claudia Witt (University Zurich), Toby Lasserson (Cochrane Editorial Unit), Taixiang Wu (Chinese Clinical Trial Registry, Chinese Cochrane Center), Larissa Shamseer (Ottawa Hospital Research Institute; University of Ottawa), Cynthia Mulrow (senior deputy editor, Annals of Internal Medicine)

  • Competing interests: None declared.

  • Funding: PRISMA harms was partly funded by Alberta Innovates, Health Solutions. The researchers were fully independent from funders.

  • Ethical approval: Approval granted by the University of Alberta (no Pro00021294).

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

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