1. Dr. El-Sadr is director of the International Center for AIDS Care and Treatment Programs (ICAP) and a professor of clinical medicine and epidemiology at the Mailman School of Public Health and the College of Physicians and Surgeons, Columbia University, and chief of the Division of Infectious Diseases at Harlem Hospital Center — both in New York. Dr. Hoos is director of the Multicountry Columbia Antiretroviral Program at ICAP and assistant professor of clinical epidemiology at the Mailman School of...