Discrimination, neighborhood factors and risky drug-using networks: Explaining the socio-contextual process of HIV transmission among illicit drug users in New York City (NYC)

Experiences of discrimination and neighborhood features denoting disadvantage, influence drug use patterns. Thus, they may also influence formation of high-risk drug networks. This is important given the potential increased opportunity for HIV transmission due to risk characteristics of one's network, independent of individual drug-using risk behaviors. We combined baseline "Social Ties Associated with Risk of Transition" (START) data with 2000 US-Census data to examine whether neighborhood factors exacerbated the relationship between discrimination and high-risk drug-using networks. START is a prospective cohort of 652 non-injection drug users (NIDUs) and cross-sectional sample of newly-initiated IDUs. Population average models estimated the prevalence ratio between discrimination (due to race and drug use) and high-risk drug-using networks (≥7 networks who either use crack, heroin, inject or those drugs are used with); and whether this association was modified by neighborhood factors (education and poverty level) after accounting for individual risk behavior. Drug use discrimination was associated with high-risk drug-using networks (PR:1.09;95%CI:1.02-1.16) and this relationship was modified by neighborhoods with the highest levels of poor education (PR:1.90;95%CI:1.20-3.01;p=0.07). Interestingly, education was not a significant modifier of racial discrimination and high-risk drug-using networks, but it was important in neighborhoods with the lowest levels of poor education (PR:1.51;95%CI:1.01-2.26). Similarly, high-risk drug-using networks and racial discrimination was important in neighborhoods with the least amount of poverty but drug use discrimination was important among neighborhoods with the most poverty. This suggests that various types of discrimination may manifest differently by neighborhood structure with respect to HIV-risk network structure. Further investigation is warranted.