Just 60 percent of AIDS patients in Africa still take the drugs they need to stay alive two years after starting treatment, researchers reported, noting a grim reason many stopped: death.

Of the patients found no longer to be taking the drugs after two years, 40 percent died and the rest missed scheduled appointments, failed to pick up medication or may have transferred to other clinics. A small percentage stopped their treatment but continued to get other medical care at clinics where they started AIDS drugs.

"I don't want people losing heart from this, even though 60 percent isn't fabulous," said Sydney Rosen, an assistant professor at Boston University's School of Public Health, who led the study. The study was published Monday in the Public Library of Science Medicine journal.