1. The Harborview Injury Prevention and Research Center, University of Washington, Seattle, Washington.
2. Department of Pediatrics, University of Washington, Seattle, Washington.
3. Department of Epidemiology, University of Washington, Seattle, Washington.
4. Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington.
5. Department of Emergency Medicine, Children's Hospital of Philadelphia and the University of Pennsylvania, Philadelphia, Pennsylvania.
6. Department of Neurological Surgery, University of Washington, Seattle, Washington.
7. Department of Biostatistics, University of Washington, Seattle, Washington.
8. Department of Psychiatry, University of Washington, Seattle, Washington.
9. Department of Health Services, University of Washington, Seattle, Washington.
10. Pediatric Developmental Services, Mary Bridge Children's Hospital, Tacoma, Washington.
11. Department of Rehabilitation Medicine, University of Washington, Seattle, Washington.