Gender differences in progression to AIDS and death from HIV seroconversion in a cohort of injecting drug users from 1986 to 2001 (2004)

Background: Although the consensus is that gender does not influence HIV progression, its relevance may depend on the setting. Aim: To study gender differences in HIV progression to AIDS and death from 1986 to 2001 in a cohort of injecting drug user (IDU) seroconverters in Spain. Methods: Risk of AIDS and death in persons infected for the same length of time were compared through Kaplan-Meier, allowing for late entry, and Cox regression adjusting for gender, age, and calendar period (before 1992, 19921995, 19961998, 19992001) fitted as time dependent covariates. Results: Of 929 IDU, 24.7% were women. Median seroconversion year was 1993.3 for men and women. 44% of women and 34% of men received antiretroviral therapy. Risk of AIDS was lower in women in univariate (hazard ratio (HR) 0.72; 95%CI:0.51 to 1.01) and multivariate analyses (HR 0.73 95%CI:0.52 to 1.03). A 46% reduction in risk of AIDS for period 19992001 compared with 19921995 was seen in both men and women (HR: 0.56 (95%CI:0.36 to 0.87). As for mortality, womens risk of death was lower univariately (HR 0.67 95%CI:0.45 to 0.99) although compared with 199295, men experienced a 34% reduction in mortality during 19992001 (HR 0.66 95%CI:0.40 to 1.01), which was not statistically significant in women. Conclusions: HIV progression was lower in female IDU before and after 1997 and their uptake of antiretroviral therapy was higher than male IDU. The inability to detect a reduction in mortality for women during 19992001 is probably attributable to lack of power. Differences in severity of addiction, drug using patterns, and competing causes of death may explain these findings.