Are there gender differences in starting protease inhibitors, HAART, and disease progression despite equal access to care?

OBJECTIVES: To describe gender differences in starting and response to treatment regimens and long-term clinical outcome in a well-characterized regional population from the Southern Alberta HIV Clinic (SAC) of 1403 patients, where all medical care for HIV, including physician fees, laboratory tests, and antiretroviral drug costs is provided free of charge.
DESIGN: Observational cohort study.
METHODS: Cox proportional hazards models were used to examine the relative risk of starting treatment regimens and disease progression (new AIDS-defining illness or death).
RESULTS: There are 126 women in the SAC (9.0%). The median CD4 lymphocyte count at first visit among all patients was 350 cells/mm3, and was significantly higher among women than men (428 cells/mm3 versus 345 cells/mm3, respectively; p = 0.0024). Participating women were less well educated than participating men; 29% of women did not proceed beyond a tenth grade education compared with 13% of men; only 28% of women went to college or received a degree in contrast to 40% of men (p <. 001). The proportion of women in the cohort has increased over the past 5 years (p <.001). During a median follow-up period of 35 months that dates back as far as 1985, 572 patients (40.8%) died or progressed to a new AIDS-defining illness, of whom 30 were women (5. 2%). In a multivariate Cox model stratified by calendar quartile of first visit and adjusted for latest CD4, AIDS status, age, exposure group, education, and prior treatment, women were significantly less likely to start highly active antiretroviral therapy (HAART; defined as at least three antiretrovirals taken consecutively; relative hazard [RH], 0.69; 95% confidence interval [CI], 0.49-0.98; p =.033), significantly less likely to start a protease inhibitor containing treatment regimen (RH, 0.71; 95% CI, 0.52-0.98; p =.040) and significantly less likely to start a HAART regimen including a protease inhibitor (RH, 0.69; 95% CI, 0.48-1.00; p =.049). After adjustment for potentially confounding variables such as CD4 lymphocyte count and treatment regimen, no difference in disease progression was found between men and women (RH, 0.77; 95% CI, 0. 49-1.19; p =.24). Among patients who started HAART, the CD4 lymphocyte count and viral load at starting treatment regimens was similar between men and women, as were the immunologic and virologic response following initiation of treatment.
CONCLUSIONS: Despite free access to antiretrovirals, women in the SAC were significantly less likely to start HAART treatment regimens, and the reasons for this need further investigation. Response to treatment was similar between genders. No evidence was found for a poorer long-term clinical outcome in women, but given the proven large clinical benefits of HAART, this may change in the future.