1. Department of Epidemiology, Robert Stempel College of Public Health and Social Work, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA
2. Center for Research on U.S. Latino HIV/AIDS and Drug Abuse (CRUSADA), Florida International University, Miami, FL 33199, USA
3. Drexel Hill, PA 19026, USA
4. Center for Studies on Addiction, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
5. Regional West Medical Center, Scottsbluff, NE 69361, USA
6. HIV/AIDS Prevention Research Division, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA