1. Department of Pediatrics, Primary Children’s Hospital and University of Utah, Salt Lake City, Utah;
2. Service d’accueil des urgences pédiatriques, Necker-Enfants Malades University Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France;
3. Epidémiologie Clinique et Évaluation Économique Appliquées aux Populations Vulnérables, Institut National de la Santé et de la Recherche Médicale, Paris, France;
4. Children’s Hospital at Dartmouth-Hitchcock, Lebanon, New Hampshire;
5. Department of Pediatrics, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire;
6. Service de Pédiatrie, Antoine Béclère University Hospital, Assistance Publique-Hôpitaux de Paris, Clamart, France; and
7. Centre for Research in Epidemiology and Population Health, Villejuif, France