Despite a "more challenging" patient population, San Francisco General Hospital has topped U.S. News and World Report's annual list of the nation's best AIDS hospitals-for the sixth year. The demographics of the epidemic have shifted a great deal in the past five years, according to Dr. Paul Volberding, director of the AIDS program.

"The early wave of infections [affected] middle-class gay men. Now it's poor people, the homeless and injection-drug users," he says.

Other hospitals in the top five are Massachusetts General and medical centers at Johns Hopkins, UCLA and the University of California San Francisco.