Differential improvement in survival among patients with AIDS after the introduction of HAART

Abstract

We explored changes in the survival of patients with AIDS (PWA) according to the availability of antiretroviral drugs (1994-2002). We tested whether changes in the hazard ratio of progression to death (HR) have been homogeneous among various groups of PWA. We included 4158 PWA diagnosed in Paris, notified to the French National Surveillance Institute by 2002. Four calendar periods were defined: monotherapy (1994-95), bitherapy-HAART transition (1996), early HAART (1997-99), late HAART (2000-October 2002). HR were calculated with Cox models, including the calendar period, modelled as a time dependent covariate. Models were stratified by age, transmission category, CD4 cell count, and AIDS-defining illnesses (ADI) group. Cumulative survival at 60 months increased from 44.0% (before July 1996) to 75.6% (after July 1996) and median survival increased from 31.9 months to >76 months. Adjusted HR reached a minimum in the late HAART period (HR 0.22, 95% CI: 0.19-0.26). No difference in the decrease of the HR has been found by age. HR decreased and was marked during the late HAART period across all HIV transmission categories, including intravenous drug use. HR decreased significantly for all ADIs groups, including tumours. Among PWA diagnosed with tuberculosis, the HR decreased significantly only in the late HAART period. HR decrease was stronger for PWA with a CD4 cell count < or =200/mm(3). Substantial improvements in survival after the introduction of HAART were found for all PWA but varied by specific ADIs and the degree of immunosuppression.