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Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial

BMJ 2009; 339 doi: (Published 29 October 2009) Cite this as: BMJ 2009;339:b4146
  1. Ian G Stiell, professor and chair1, senior scientist4,
  2. Catherine M Clement, research program manager4,
  3. Jeremy Grimshaw, full professor4,
  4. Robert J Brison, professor6,
  5. Brian H Rowe, professor and research director5,
  6. Michael J Schull, associate professor7,
  7. Jacques S Lee, assistant professor7,
  8. Jamie Brehaut, assistant professor2, scientist4,
  9. R Douglas McKnight, clinical associate professor9,
  10. Mary A Eisenhauer, associate professor8,
  11. Jonathan Dreyer, research director and professor8,
  12. Eric Letovsky, associate professor7,
  13. Tim Rutledge, associate professor7,
  14. Iain MacPhail, emergency medicine physician9,
  15. Scott Ross, emergency medicine physician5,
  16. Amit Shah, assistant professor8,
  17. Jeffrey J Perry, associate professor1, scientist4,
  18. Brian R Holroyd, professor and department head5,
  19. Urbain Ip, emergency medicine physician9,
  20. Howard Lesiuk, associate professor3,
  21. George A Wells, professor24
  1. 1Department of Emergency Medicine, University of Ottawa, Canada
  2. 2Department of Medicine, University of Ottawa, Canada
  3. 3Division of Neurosurgery, University of Ottawa, Canada
  4. 4Clinical Epidemiology Program, Ottawa Hospital Research Institute,
  5. 5Department of Emergency Medicine, University of Alberta, Edmonton, Canada
  6. 6Department of Emergency Medicine, Queen’s University, Kingston, Canada
  7. 7Division of Emergency Medicine, University of Toronto, Canada
  8. 8Division of Emergency Medicine, University of Western Ontario, London, Canada
  9. 9Department of Emergency Medicine, University of British Columbia, Vancouver, Canada
  1. Correspondence to: I G Stiell istiell{at}
  • Accepted 7 August 2009


Objective To evaluate the effectiveness of an active strategy to implement the validated Canadian C-Spine Rule into multiple emergency departments.

Design Matched pair cluster randomised trial.

Setting University and community emergency departments in Canada.

Participants 11 824 alert and stable adults presenting with blunt trauma to the head or neck at one of 12 hospitals.

Interventions Six hospitals were randomly allocated to the intervention and six to the control. At the intervention sites, active strategies were used to implement the Canadian C-Spine Rule, including education, policy, and real time reminders on radiology requisitions. No specific intervention was introduced to alter the behaviour of doctors requesting cervical spine imaging at the control sites.

Main outcome measure Diagnostic imaging rate of the cervical spine during two 12 month before and after periods.

Results Patients were balanced between control and intervention sites. From the before to the after periods, the intervention group showed a relative reduction in cervical spine imaging of 12.8% (95% confidence interval 9% to 16%; 61.7% v 53.3%; P=0.01) and the control group a relative increase of 12.5% (7% to 18%; 52.8% v 58.9%; P=0.03). These changes were significant when both groups were compared (P<0.001). No fractures were missed and no adverse outcomes occurred.

Conclusions Implementation of the Canadian C-Spine Rule led to a significant decrease in imaging without injuries being missed or patient morbidity. Final imaging rates were much lower at intervention sites than at most US hospitals. Widespread implementation of this rule could lead to reduced healthcare costs and more efficient patient flow in busy emergency departments worldwide.

Trial registration Clinical trials NCT00290875.


  • We thank the physicians, nurses, and radiology technicians at the intervention hospitals for their cooperation with the study; the following research staff at the study hospitals: Vancouver General, Vancouver, British Columbia (Jan Buchanan); London Health Sciences Centre, London, Ontario (Evelyn Gilkinson); Ottawa Hospital-Civic Campus, Ottawa, Ontario (Kim Bradbury); Sturgeon, St Albert, Alberta (Michelle Pachal); North York General, Toronto, Ontario (Jodie Hale, Andrea Ennis); Surrey Memorial, Surrey, British Columbia (Linda Gormley); University of Alberta, Edmonton, Alberta (Harris Lari, Terry Shewchuk); Sunnybrook and Women’s College Health Sciences Centre, Toronto, Ontario (Sharon Ramagnano, Deborah Wright); Kingston General, Kingston, Ontario (Kathy Bowes); Royal Columbian, New Westminster, British Columbia (Percy MacKerricher); Credit Valley, Mississauga, Ontario (Jeannie Brewster, Jennifer Yantha); St Thomas Elgin, St Thomas, Ontario (Lorraine Rollins); our colleagues at the Ottawa Hospital Research Institute (Christine Leclair, Sheryl Domingo, My-Linh Tran, and Irene Harris) for their assistance with this project; and Carol Bennett for invaluable assistance in preparing the manuscript.

  • Funding: This study received support for peer review from the Canadian Institutes of Health Research. The funding agency had no role in the design, conduct, or reporting of the study.

  • Competing interests: None declared.

  • Ethical approval: This study was approved by the hospital research ethics boards, without the need for informed consent as all patients were treated with the same imaging protocol. Individual patients were not randomised and the degree of risk was judged to be minimal. A proposed data safety monitoring board was not convened because no adverse events occurred during the study.

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