1. Division of Emergency Medicine, Boston Children's Hospital , Boston, Massachusetts , USA
2. Division of Emergency Medicine, Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
3. Division of Emergency Medicine, Nemours Children's Hospital Delaware , Wilmington, Delaware , USA
4. Pediatric Emergency Medicine, Children's Hospital of Wisconsin , Milwaukee, Wisconsin , USA
5. Division of Emergency Medicine, Children's Hospital of Pittsburgh , Pittsburgh, Pennsylvania , USA
6. Department of Emergency Medicine, Children's Minnesota , Minneapolis, Minnesota , USA
7. Department of Emergency Medicine, Rhode Island Hospital , Providence, Rhode Island , USA