1. Division of Emergency Medicine
2. Department of Medicine, Children’s Hospital Boston and Harvard Medical School, Boston, Massachusetts
3. Division of Emergency Medicine, Department of Pediatrics, Nemours/Alfred I. duPont Hospital for Children, Jefferson Medical College, Wilmington, Delaware
4. Division of Infectious Diseases, The Children’s Hospital Philadelphia, Philadelphia, Pennsylvania
5. Departments of Pediatrics and Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania
6. Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio