1. University of Colorado-AMC, Aurora, Colorado
2. Northwestern University Feinberg School of Medicine, Chicago, Illinois
3. Center for Biostatistics in AIDS ResearchHarvard School of Public Health, Boston, Massachusetts
4. New York University School of Medicine, New York, New York
5. University of North Carolina School of Medicine, Chapel Hill, North Carolina
6. Social and Scientific SystemsSilver Spring, Maryland
7. Frontier Science & Technology Research FoundationInc, Amherst, New York
8. Beth Israel Medical Center, New York, New York
9. Rush University Medical CenterChicago, Illinois