1. Division of General Pediatrics & Adolescent Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland.
2. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
3. The Adolescent Initiative, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
4. Adolescent Clinical Research, Burgess Clinic, Children's National Medical Center, Washington, District of Columbia.
5. Whitman-Walker Health, Washington, District of Columbia.
6. Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.