PROJECT SUMMARY/ABSTRACT An estimated 3.5 million youth between the ages of 18 and 25 experience homelessness in the U.S. each year. Relative to their stably housed peers, youth experiencing homelessness (YEH) are vulnerable to a multitude of risks affecting their health and well-being, including substance abuse, mental health challenges, victimization, and death. YEH are also more likely to engage in risky sexual behaviors and are up to 10 times more likely to contract HIV compared to their housed peers. Key to understanding the HIV risk and prevention behaviors of YEH are their social networks—their web of personal social interactions and relationships. Increased HIV risk among YEH has been tied to involvement in social networks with risk-taking peers and predominantly the consequence of unsafe sex over injection drug use and needle sharing. Conversely, connections to family and pro-social peers have been demonstrated to influence HIV prevention behaviors among YEH, including condom use and HIV testing. However, the effect of different living situations among YEH—and particularly of precarious housing (i.e., “couch-surfing” or temporarily staying with others)—on HIV risk and prevention behaviors remains largely unknown. A sizable portion of the YEH population reports living in precarious housing, and current evidence also suggests that that youth of color and youth identifying as LGBTQ+ are more likely to be precariously housed compared to other YEH, populations that also carry disproportionate risk for HIV. The proposed mixed-methods study has three aims. Aims 1 and 2 will use an existing dataset from Have You Heard?, a longitudinal study of a peer leader training intervention for HIV prevention among YEH in Los Angeles, California. Aim 1 will entail conducting an egocentric social network analysis to investigate whether precarious housing and social support are associated with HIV risk (e.g., transactional sex, condomless sex, sex under the influence, concurrent sex partners) and prevention (e.g., recent HIV testing and PrEP awareness and use) behaviors among YEH. Aim 2 will use latent class analysis to explore the heterogeneity of YEH based on living situation and social support networks in order to examine (a) whether LGBTQ+ identity, racial/ethnic minority status, and duration of homelessness relate to emergent subgroups and (b) whether HIV risk and prevention behaviors vary across these emergent subgroups. Aim 3 will entail conducting qualitative interviews with precariously housed youth (n = 20) to explore how social support networks and housing status influence HIV risk and prevention behaviors among precariously housed YEH. This study will expand knowledge regarding HIV risk and prevention behaviors among YEH, paving the way for the development of more tailored HIV prevention interventions for this vulnerable population. In addition, the PI will receive training in understanding HIV risk and prevention among vulnerable youth populations, advanced statistical methods, and mixed-methods research; gain experience conducting HIV-related research with YEH; and opportunities for professional development.

PROJECT NARRATIVE Youth experiencing homelessness (YEH) are disproportionately affected by HIV compared to their stably housed peers. However, little is known about the unique risks faced by YEH who are precariously housed (i.e., “couch-surfing” or temporarily staying with others). The proposed study will examine how the social support networks and living situations of precariously housed YEH impact their HIV risk and prevention behaviors.