1. Department of Systems, Populations and Leadership, School of Nursing, University of Michigan, 400 North Ingalls Street, Room 4156, Ann Arbor, MI 48109, USA
2. Population Studies Center, Institute for Social Research, University of Michigan, 426 Thompson St, Ann Arbor, MI 48104, USA
3. Department of Sociology, University of Michigan, 500 S. State Street, Ann Arbor, MI 48109, USA
4. HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute and Columbia University, 1051 Riverside Drive, Unit 15, New York, NY 10032, USA