Natalie Le Sage

Years since first academic appointment: More than 16 years

Title: Validation of the PoCS rule, a clinical decision rule integrating the use of biomarkers for early detection of persistent symptoms after a mTBI

Introduction: Each year in Canada, the incidence of Mild Traumatic Brain Injury (mTBI, cerebral concussion) is estimated at 500 cases per 100 000. Given that between 10 and 56 % of patients with mTBI develop persistent post-concussion symptoms (PPCS) for more than three months, there is a pressing need for physicians and nurses in the ED and other primary care facilities to have access to a simple, quick, and reliable clinical decision rule to predict complications or persistent symptoms after a mTBI. Our preliminary data has shown that predictive models solely based on clinical factors are not sufficiently accurate to identify all high-risk patients. Therefore, we have integrated biomarkers with clinical characteristics to develop our final model called the PoCS Rule (Post Concussion Symptoms). A new cohort of patients is now required to validate this model. Last year, we were preparing the CIHR grant proposal for this project. It was funded, and so we are now working for the implementation of this multicenter protocol.

Objectives: The main objective of this project is to validate the PoCS Rule in terms of sensitivity, specificity, PPV and NPV for the follow up of patients at risk of persistent symptoms.

Methods: Seven hospitals will participate for the recruitment of the patients. At this time, all hospitals had submitted the protocol to their Research Ethicla Board. We got two final approbations,  two conditionnal approbations, and three are under REB evaluation. Institutional arrangements are currently going on for data/sample transfers and for laboratory collaborative agreements. The recruitment has began at CHU de Quebec (HEJ and CHUL). On March 16th, the PI and the coordinator will have visited all recruiting sites except one. We will recruit 650 mTBI patients at seven Canadian emergency departments to validate the final model. Inclusion criteria are: patient aged ≥ 14 years old with a documented mTBI <24 hrs, with a GCS of ≥ 13 when evaluated in the ED and non hospitalized. Relevant clinical data as well as blood samples for biomarkers will then be collected. A standardized telephone questionnaire (Rivermead Post-Concussion symptoms Questionnaire and other validated questionnaires) will be administered to all included patients at 7 and 90 days after their initial visit. The primary outcome measure will be the presence of persistent symptoms at 90 days after mTBI. Next, based on our integrated knowledge translation model, we will join forces with selected government agencies and stakeholders – Québec INESSS, Ontario Neurotrauma Foundation (ONF), etc. – in order to promote knowledge translation of the model and to plan its future implementation in practice.

Significance: This project will allow the validation required to create a clinically useful tool intended for use at the first ED visit, in accordance with the methodological standards of clinical decision rules. Once validated, this tool will identify patients with the most likelihood of adverse outcomes and allow clinicians to refer them properly to adequate follow up. In addition, this project will promote the future implementation of the PoCS Rule and knowledge transfer activities. It will also enable future research on the evaluation of interventions in patients at risk.

Question to the audience: What would be the better ways for knowledge translation?

PI: Natalie Le Sage, Université Laval, Québec


  • Patrick Archambault, Université Laval, Québec
  • Simon Berthelot, Université Laval, Québec
  • Jean-Marc Chauny, Université de Montréal
  • Julien Clément, INESSS
  • Élaine De Guise McGill University
  • Marcel Émond, Université Laval, Québec
  • Jérôme Frenette, Université Laval, Québec
  • Eddy Lang, University of Calgary
  • Jacques Lee, University of Toronto
  • Éric Mercier, Monash University, Australia
  • Lynne Moore, Université Laval, Québec
  • Marie-Christine Ouellette, Université Laval, Québec
  • Jeff Perry, Ottawa Hospital Research Institute, Ottawa
  • Peter Cameron, Monash University, Australia