HAS THE RATE OF PROGRESSION TO AIDS CHANGED IN RECENT YEARS

Objectives: To investigate whether the rate of progression to AIDS has changed over lime by testing an effect of the year of seroconversion on AIDS onset (Centers for Disease Control and Prevention 1987 revised classification), next to an effect of the calendar period of follow-u p. Design: French multicentre prospective study of 385 homosexual and heterosexual subjects and 231 subjects from a multicentre study of Eur opean injecting drug users (IDU), all with a documented dale of HIV-1 seroconversion. Method: The effect of the year of seroconversion was c ompared by the log-rank test. Crude and adjusted relative hazard (ARH) were quantified using the Cox model. Calendar period of follow-up was studied separately for sexual exposure group and IDU and treated as a rime-dependent variable in a Cox model. Results: In the 616 study sub jects the year of seroconversion was not significantly related re AIDS occurrence (n = 108): the ARH was 0.88 [95% confidence interval (CI), 0.56-1.38] for those who seroconverted in 1988-1989, and 1.17 (95% CI , 0.61-2.25) for those who seroconverted after 1989, compared with tho se who seroconverted before 1988. In the sexual exposure group, a clea r trend rewards less rapid progression to AIDS was observed in subject s followed in 1991-1992 (ARH, 0.49; 95% CI, 0.24-0.99) and after 1992 (ARH, 0.54; 95% CI; 0.24-1.21), compared with those followed before 19 91. This favorable trend was not observed in IDU despite a significant decrease over time of Pneumocystis carinii pneumonia as AIDS-defining illness. Conversely to sexual exposure groups, the frequency of antir etroviral treatment (mainly zidovudine) prescription was still low dur ing the most recent calendar periods in IDU when tile CD4 co-int thres hold of 200 x 10(6)/l was reached. Conclusions: No evidence was found of a change in the rate of progression to AIDS in subjects who serocon verted ir recent years. Furthermore, conversely to sexual exposure gro ups, the lack of favorable trends in IDU users followed in recent year s suggest that health-care systems are not always adapted to their lif estyles.