CD4 and AIDS: Factors independently associated with shorter survival included: AIDS diagnosis during the 1994-1996 (HR 2.0) and 1988-1993 (HR 3.2) periods; 50 years of age or more (HR 2.0); exposure category of injection drug users (IDU) (HR 1.5); 8 years of schooling or less (HR 1.4); no schooling (HR 2.1); and CD4+ counts between 350 and 500 cells/mm3 (HR 1.2) and less than 350 cells/mm3 at AIDS diagnosis (HR 1.3).