1. Coordinating Centers for Biometric Research, Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA
2. The Kirby Institute, University of New South Wales, Sydney, NSW, Australia
3. Copenhagen HIV Programme, University of Copenhagen, Copenhagen, Denmark
4. Medical Research Council, London, UK
5. Sponsored Projects Administration, University of Minnesota, Minneapolis, MN, USA
6. Veterans Affairs Medical Center, Washington, DC, USA