1. Pediatric Emergency Department, Cruces University Hospital, University of the Basque Country, Bilbao, Basque Country, Spain;
2. Children’s Emergency Department, Starship Children’s Hospital and Liggins Institute, University of Auckland, Auckland, New Zealand;
3. Departamento de Emergencia Pediátrica, Centro Hospitalario Pereira Rossell, Montevideo, Uruguay;
4. Clinical Epidemiology Unit, Cruces University Hospital, BioCruces Health Research Institute, Basque Country, Spain; and
5. Department of Emergency Medicine and Pediatrics, Davis School of Medicine, University of California, Sacramento, California