1 Emergency Department, Royal Children's Hospital, Melbourne, Parkville, Victoria, Australia; Department of Paediatrics, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Melbourne, Parkville, Victoria, Australia.
2 Murdoch Children's Research Institute, Melbourne, Parkville, Victoria, Australia; Emergency Department, Bristol Royal Hospital for Children, Bristol, United Kingdom; Academic Department of Emergency Care, University of the West of England, Bristol, United Kingdom.
3 Murdoch Children's Research Institute, Melbourne, Parkville, Victoria, Australia; Department of Women's and Children's Health, University of Padova, Padova, Italy.
4 Starship Children's Health, Grafton, Auckland, New Zealand; Liggins Institute, University of Auckland, Grafton, Auckland, New Zealand.