1 Centre for Child Health, Behavior and Development, Seattle Children's Research Institute, Seattle, WA, USA Departments of Anesthesiology Pediatrics, and Psychiatry, University of Washington, Seattle, WA, USA Departments of Pediatrics and Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada Centre for Pediatric Pain Research, IWK Health Centre, Halifax, NS, Canada Division of Clinical, Social and Administrative Pharmacy, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada Department of Clinical Psychology, Justus Liebig University, Gießen, Germany.