1. Center for AIDS Prevention Studies, University of California, San Francisco, San Francisco, California
2. Center for Health Studies, Group Health Cooperative, Seattle, Washington
3. HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute and Columbia University, New York, New York
4. Center for Community Health, University of California, Los Angeles, Los Angeles, California
5. Center for AIDS Intervention Research, Medical College of Wisconsin, Milwaukee, Wisconsin
6. HIV Center for Comprehensive Care, St. Luke's-Roosevelt Medical Center, New York, New York