Differences in HIV Risk and Preventive Behaviors in Two Large Networks of Homeless Youth

Background: Homeless youth are at high risk for contracting HIV/AIDS, with HIV prevalence reports as high as 11% in some studies.  Research on homeless youth has consistently demonstrated that engagement with HIV risk-taking peers is strongly associated with HIV risk-taking behaviors. With one notable exception, all of this work has been done with ego-centric network data.  How HIV risk permeates larger network structures of homeless youth is relatively unknown. Such data has not been examined previously because homeless youth constitute an unbounded population and network science is unclear on the most effective methods for collecting such data.  The goal of this presentation is to present new data on two large networks of homeless youth and show the distribution of HIV risk and preventive behaviors in these two networks. 

Methods: The study utilized the event-based approach to collect unbounded social network data.  This method “bounds” individuals based on participation in a shared set of activities or events over time seems the most applicable to homeless youth.  The strategy uses drop-in centers as an artificial “boundary” from which to sample youth.  It does not depend on specific membership in a formal group, and allows social isolates and peripheral youth to be equally represented as highly-interconnected youth.  The entire population of youth accessing these agencies was eligible to participate and all youth accessing services were invited to participate. Homeless youth (13-25 years old) were recruited between October 2011 and February 2012 from two drop-in centers, one in Hollywood, CA (80.2% of the population were interviewed) and one in Santa Monica, CA (93.3% of the population were interviewed), yielding a final N of 380. 

Results: In Santa Monica, more youth were white.  Hollywood has a significantly larger population of females and non-heterosexual youth compared to Santa Monica.  Number of lifetime sex partners was significantly higher in Santa Monica.  Injection drug use was reported by 18% of youth in Santa Monica relative to 8% in Hollywood.  Reports of lifetime HIV testing were much higher in Hollywood (88%) relative to Santa Monica (73%). The distribution of these behaviors across social network space is also different, with injectors being more centrally located in the Santa Monica network.

Conclusions: There have been recent calls in the academic literature for peer-based prevention for homeless youth.  Prevention science must grapple with the heterogeneity of homeless networks and their impact on HIV risk taking in regards to potential effectiveness of peer-based prevention interventions.