Changes in survival among people with AIDS in Lazio, Italy from 1993 to 1998

Abstract

To investigate temporal changes in survival of persons with AIDS (PWA) diagnosed in Lazio, Italy. Longitudinal study of 2862 PWA registered at the AIDS Surveillance System in the period 1 January 1993 to 30 June 1997 and followed for vital status up to 31 May 1998. Hazard ratios (HR) of death were calculated by year of diagnosis and by year of follow-up, adjusting for gender, age, modality of exposure, CD4 cell count at diagnosis, and AIDS-defining illness, using the Cox proportional regression model. In the period 1 January 1993 to 31 May 1998, 1914 PWA died. The multivariate model showed a decrease of the risk of death for patients diagnosed from 1995 onward compared with patients diagnosed in 1993 [1995: HR 0.82; 95% confidence intervals (CI) 0.73-0.93; 1996: HR 0.44; 95% CI 0.38-0.51; first semester of 1997: HR 0.47; 95% CI 0.37-0.59]. The model with the year of follow-up modeled as time-dependent variable showed a statistically significant decline in the risk of death starting from the first quarter of 1997 (HR 0.62; 95% CI 0.48-0.80) and reached the minimum in the first two quarters of 1998 (first quarter: HR 0.13; 95% CI 0.08-0.21; second quarter: HR 0.14, 95% CI 0.08-0.25). There was a small difference in the magnitude of the risk estimates among genders, with a slower improvement in survival among females [first semester of 1997 for males HR was 0.51 (95% CI 0.39-0.66) whereas for females HR was 0.80 (95% CI 0.51-1.27)]. Survival of PWA in a population-based study improved significantly in the era when highly active antiretroviral therapy became available, but such improvement is not homogeneous among genders.