1. Department of Pediatrics, Division of Neurology, University of Alberta, Edmonton, Alberta, Canada.
2. Department of Pediatrics, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
3. Women and Children's Health Institute, University of Alberta, Edmonton, Alberta, Canada.
4. Independent Statistical Consultant.
5. Department of Pediatrics and Emergency Medicine, University of Ottawa, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.