Periods of Homelessness Linked to Higher VACS Index Among HIV-Positive People Who Use Drugs.

We sought to evaluate the impact of homelessness on HIV disease progression among people who use unregulated drugs (PWUD) living with HIV and test if this association was mediated by adherence to antiretroviral therapy (ART). We applied general linear mixed-effects modeling to estimate the longitudinal relationship between homelessness and the Veterans Aging Cohort Study (VACS) Index, a validated measure of HIV disease progression that predicts all-cause mortality, among a prospective cohort of PWUD. In a longitudinal model adjusted for ART adherence, homelessness was significantly associated with increased VACS Index scores and 16% of the association was mediated by ART adherence. These findings indicate that homelessness was a significant risk factor for HIV disease progression and this association was marginally mediated by ART adherence. Future studies are needed to quantify the other mechanisms (e.g., food insecurity, mental health) by which homelessness increases mortality risk among PWUD living with HIV.