Beryl A. Koblin is with the New York Blood Center, New York, NY. Margaret A. Chesney and Thomas J. Coates are with the School of Medicine, University of California, San Francisco. Marla J. Husnik and Yijian Huang are with the Statistical Center for HIV/AIDS Research and Prevention, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Wash. Sam Bozeman is with Abt Associates Inc, Cambridge, Mass. Connie L. Celum is with the Department of Medicine, University of Washington,...