1. aMontreal Children’s Hospital, Division of Pediatric Emergency Medicine, McGill University Health Centre, and Department of Biostatistics, Epidemiology, and Occupational Health, McGill University, Montreal, Quebec, Canada
2. bDivision of Emergency Medicine, Department of Pediatrics, British Columbia Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
3. cDivision of Pediatric Emergency Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, and Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
4. dSection of Pediatric Emergency Medicine, Department of Pediatrics
5. fSection of Gastroenterology, Department of Emergency Medicine, Cumming School of Medicine, University of Calgary, Calgary, Canada
6. eDepartments of Emergency Medicine and Pediatrics, University of California, Davis, School of Medicine, Sacramento, California