1. Department of Medicine, Complex Care Service, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts
2. Child Health Corporation of America, Shawnee Mission, Kansas
3. Department of Pediatrics, Children's Mercy Hospital, Kansas City, Missouri
4. Department of Pediatric Neurosurgery, Children's Hospital Boston, Boston, Massachusetts
5. Center for Clinical Effectiveness, Children's National Medical Center, Washington, District of Columbia
6. Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; and Departments of Pediatrics and Biostatistics and Epidemiology and Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania