Background
Women with HIV are globally underrepresented in clinical research. Existing studies often focus on reproductive outcomes, seldom focus on older women, and are often underpowered to assess sex/gender differences. We describe CD4, HIV viral load (VL), clinical characteristics, comorbidity burden, and use of antiretroviral therapy (ART) among women with HIV in the RESPOND study and compare them with those of the men in RESPOND.

Methods
RESPOND is a prospective, multi-cohort collaboration including over 34 000 people with HIV from across Europe and Australia. Demographic and clinical characteristics, including CD4/VL, comorbidity burden, and ART are presented at baseline, defined as the latter of 1 January 2012 or enrolment into the local cohort, stratified by age and sex/gender. We further stratify men by reported mode of HIV acquisition, men who have sex with men (MSM) and non-MSM.

Results
Women account for 26.0% (n = 9019) of the cohort, with a median age of 42.2 years (interquartile range [IQR] 34.7–49.1). The majority (59.3%) of women were white, followed by 30.3% Black. Most women (75.8%) had acquired HIV heterosexually and 15.9% via injecting drug use. Nearly half (44.8%) were receiving a boosted protease inhibitor, 31.4% a non-nucleoside reverse transcriptase inhibitor, and 7.8% an integrase strand transfer inhibitor. The baseline year was 2012 for 73.2% of women and >2019 for 4.2%. Median CD4 was 523 (IQR 350–722) cells/μl, and 73.6% of women had a VL <200 copies/mL. Among the ART-naïve population, women were more likely than MSM but less likely than non-MSM (p < 0.001) to have CD4 <200 cells/μL and less likely than both MSM and non-MSM (p < 0.001) to have VL ≥100 000 copies/mL. Women were also more likely to be free of comorbidity than were both MSM and non-MSM (p < 0.0001).

Conclusion
RESPOND women are diverse in age, ethnicity/race, CD4/VL, and comorbidity burden, with important differences relative to men. This work highlights the importance of stratification by sex/gender for future research that may help improve screening and management guidelines specifically for women with HIV.