1. Department of Neurosurgery, Division of Pediatric Neurosurgery, and
2. Department of Pediatrics, Division of Emergency Medicine, Washington University in St Louis School of Medicine, St Louis Children’s Hospital, St Louis, Missouri;
3. Departments of Emergency Medicine and Pediatrics, University of California, Davis School of Medicine, Davis Medical Center, Sacramento, California; and
4. The Data Coordinating Center, University of Utah School of Medicine, Salt Lake City, Utah