1. aDivision of Emergency Medicine, Boston Children’s Hospital, Boston, Massachusetts
2. bPerelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
3. cVot-ER, Boston, Massachusetts
4. dDepartment of Emergency Medicine, University of California, San Francisco, San Francisco, California
5. eDepartment of Emergency Medicine, University of California, San Francisco, San Francisco, California
6. fDepartment of Pediatrics, Harvard Medical School, Boston, Massachusetts
7. gDepartment of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
8. hDepartment of Emergency Medicine, Harvard Medical School, Boston, Massachusetts