1. Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
2. School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
3. Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
4. British Columbia Injury Research & Prevention Unit, Vancouver, British Columbia, Canada
5. Child & Family Research Institute, Vancouver, British Columbia, Canada
6. British Columbia Children's Hospital, Vancouver, British Columbia, Canada