[1] Cornell Univ, Weill Med Coll, Dept Med, Div Int Med & Infect Dis,Cornell Clin Trials Unit, New York, NY 10021 USA
[2] Harvard Univ, Sch Publ Hlth, Stat & Data Anal Ctr, Boston, MA 02115 USA
[3] Univ N Carolina, Chapel Hill, NC USA
[4] Univ Minnesota, Minneapolis, MN USA
[5] Univ Calif San Diego, San Diego, CA 92103 USA
[6] Stanford Univ, Med Ctr, Palo Alto, CA 94304 USA
[7] Pharmacia & Upjohn Inc, Kalamazoo, MI 49001 USA
[8] Social & Sci Syst, Rockville, MD USA
[9] NIAID, Div AIDS, NIH, Bethesda, MD 20892 USA
[10] Ohio State Univ, Columbus, OH 43210 USA
[11] Univ Miami, Sch Med, Miami, FL USA