Background:  Consensus is that gender does not influence HIV progression. However, ongoing substance abuse or co-morbid diseases among HIV-infected injecting drug users (IDU) influence a number of other health outcomes, including AIDS survival and mortality. We studied gender differences in HIV progression to AIDS and death from the 1980s to 2001 in a cohort of seroconverter IDU in Spain.

Methods:  Risk of AIDS and death in patients with comparable duration of HIV infection were analyzed through Kaplan-Meier and Cox regression adjusting for gender, age, and calendar period (before 1992, 1992-1995, 1996-1998,1999-2001) fitted as time-dependent covariates.

Results:  Of 929 IDU, 24.7% were women. Overall, median seroconversion year was 1993.3; 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 - 1.01) and multivariate analyses (HR 0.73 95% CI: 0.52 - 1.03). A 46% reduction in risk of AIDS for the period 1999-2001 compared with 1992-1995 was seen in both men and women (HR: 0.56, 95% CI: 0.36 - 0.87). Women showed a lower risk of death than men in crude analyses (HR 0.67, 95% CI 0.45 - 0.99). Kaplan-Meier survival curves show how the risk of death was lower in women compared to men (Log rank p = 0.0479); 36% of  men had died 10 years after seroconversion compared with 24% of women. Also, univariate Cox regression showed a 33% reduction in the risk of death for women (HR 0.67, 95% CI: 0.45 - 0.99) compared with men. However, male IDU experienced a 34% reduction in mortality during the last period (1999-2001) compared with 1992-1995 (HR 0,66, 95% CI: 0.40 - 1.01).

Conclusions:  Women with a history of substance abuse and HIV infection are not more likely to experience poor health and survival. In our setting, access to medical care and ART, and substance abuse treatment have clearly increased health outcomes in HIV-positive women.

Keywords: HIV progression; seroconverters; HAART