1. Department of Behavioral and Community Health Sciences, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.
2. Center for LGBT Health Research, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.
3. Division of Adolescent and Young Adult Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania.
4. Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
5. Department of Medicine, Georgetown University Medical Center, Washington, District of Columbia.
6. Department of Family Science, School of Public Health, University of Maryland, College Park, Maryland.