1. Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts.
2. Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
3. Division of Emergency Medicine, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania.
4. Pediatric Emergency Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin.
5. Division of Emergency Medicine, A.I. Dupont Hospital for Children, Wilmington, Delaware.
6. Departments of Pediatrics and Emergency Medicine, Rhode Island Hospital, Providence, Rhode Island.