1. Department of Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada;
2. Division of Emergency Medicine and
3. Children’s Health Research Institute, London Health Sciences Centre, London, Ontario, Canada;
4. Department of Pediatrics and Alberta Research Centre for Health Evidence,
5. Department of Pediatrics, Faculty of Medicine and Dentistry, and
6. Women and Children’s Health Research Institute, University of Alberta, Edmonton, Alberta, Canada;
7. Department of Pediatrics, Children’s Hospital of Eastern Ontario, Ottawa, Ontario, Canada;
8. Centre Hospitalier Universitaire Sainte-Justine and Université de Montréal, Montréal, Québec, Canada; and
9. BC Children’s Hospital and University of British Columbia, Vancouver, British Columbia, Canada