1. From the Centre for Health Policy (X.X., L.H., K.D.), Melbourne School of Population and Global Health, The University of Melbourne, Victoria; Emergency Department (D.H.), Queensland Children's Hospital; University of Queensland (D.W.H.); Mater Research Institute (D.H.), Brisbane, Queensland; Emergency Department (M.L.B.), Perth Children's Hospital; Divisions of Emergency Medicine and Paediatrics (M.B.), University of Western Australia, Perth; Department of Emergency Medicine (A.D., S.H., M.T.M., J...