1. Mailman School of Public Health, Columbia University, New York, New York
2. Division of Epidemiology, Services, and Prevention Research, National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland
3. College of Osteopathic Medicine, Nova Southeastern University, Ft Lauderdale, Florida
4. School of Public Health, University of Michigan, Ann Arbor
5. The Fenway Institute, Harvard Medical School, Boston, Massachusetts
6. School of Public Health, University of Alabama at Birmingham, Birmingham
7. Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill