Network Mixing and Network Influences Most Linked to HIV Infection and Risk Behavior in the HIV Epidemic Among Black Men Who Have Sex With Men

Objectives. We evaluated network mixing and influences by network members upon Black men who have sex with men.Methods. We conducted separate social and sexual network mixing analyses to determine the degree of mixing on risk behaviors (e.g., unprotected anal intercourse [UAI]). We used logistic regression to assess the association between a network “enabler” (would not disapprove of the respondent’s behavior) and respondent behavior.Results. Across the sample (n = 1187) network mixing on risk behaviors was more assortative (like with like) in the sexual network (r_sex, 0.37–0.54) than in the social network (r_social, 0.21–0.24). Minimal assortativity (heterogeneous mixing) among HIV-infected men on UAI was evident. Black men who have sex with men reporting a social network enabler were more likely to practice UAI (adjusted odds ratio = 4.06; 95% confidence interval = 1.64, 10.05) a finding not observed in the sexual network (adjusted odds ratio = 1.31; 95% confidence interval = 0.44, 3.91).Conclusions. Different mixing on risk behavior was evident with more disassortativity among social than sexual networks. Enabling effects of social network members may affect risky behavior. Attention to of high-risk populations’ social networks is needed for effective and sustained HIV prevention.The HIV epidemic among men who have sex with men (MSM) has not only grown to alarming levels overall, but it also is one that demonstrates significant and marked racial disparities. In 2008, 28% of MSM with new HIV infection were Black, and among MSM aged 13 to 29 years, the number of new infections in Black MSM was nearly twice that of White MSM.1,2Traditional epidemiological approaches have made limited headway in explaining these findings because they tend to focus on the role of individual risk behaviors in shaping rates of HIV infection. The higher rates of HIV among Black MSM may not be explained by individual-level risk behaviors alone, and instead may be attributed in part to social and sexual network factors.3,4 But efforts to further illuminate these factors have been largely unsuccessful as they have often used sampling methodologies that can distort accurate measurement of existing networks of these MSM (e.g., lack of weighting and focus on most recent sexual partner).5,6 Furthermore, up until now, network analyses have not examined Black MSM’s nonsexual social networks; such networks may contribute to the disparities observed (e.g., lack of embedded social network members7) and might provide opportunities for future interventions.Some research has explained disparities in HIV rates by examining sexual network mixing patterns within and between racial subgroups.8,9 Previously, we demonstrated that higher rates of sexually transmitted infections (STIs) within the African American community were related to sexual network mixing patterns.10 Higher levels of disassortative mixing—core high-risk groups mixing with peripheral low-risk groups—within the African American community, combined with limited interracial mixing, was a major contributor for the disproportionately higher rates of STIs among Blacks than among Whites. Similar sexual network mixing explanations have been demonstrated among Blacks in the Southeastern United States.11 Drug use behavior was found to be highly assortative (like behavior with like), whereas sexual behavior in the form of concurrent (or simultaneous) partnerships was minimally assortative.In contrast to the attention devoted to sexual12–17 and drug-use networks,18–23 comparatively little research has been conducted on how nonrisk social networks comprising MSM’s close friends and family members can affect STI and HIV transmission, with a few notable exceptions.7,24,25 Social learning and differential association theories26,27 hold that risky behaviors, including rationalizations for them, diffuse through social networks of close ties. Furthermore, network members influence high-risk behavior by virtue of the behavioral examples they provide, the normative pressures they exert, and MSM’s perceptions of these influences.28–30 Research has shown in a variety of contexts that risky sexual and substance use behavior is affected by individuals’ perceptions of what their network members do, regardless of whether those perceptions are accurate.31–33 Studying Black MSM’s normative contexts may help researchers identify not only those social conditions that facilitate risky behavior, but also potential network influences that can be exploited or modified to encourage the spread of HIV prevention behavior through modification of a social network. To date, most work that has examined the indirect role of social networks on the spread of HIV has focused primarily on the role of having social network ties in general, but has not specified the mechanisms through which social network ties affect the risk behavior of MSM.34,35Formal social network analysis of high-risk populations has focused on MSM and injecting drug users in general and not specifically on Black MSM.25,36 One recent pilot study37 demonstrated that sexual partners of Black MSM were mostly introduced through friends. Known risk behaviors associated with HIV infection and that could be “transmitted” through a social network include sex-drug use38 and unprotected anal intercourse (UAI). Moreover, group sexual intercourse has also recently gained increased attention as an important risk practice39,40 that can complicate network analysis.41 Important influences and practices such as these, however, have not been previously explored through social network analysis within Black MSM despite this population’s position as a group with the highest risk of HIV infection in the United States. Furthermore, network patterns that potentially confer risk, such as disassortative social mixing, have also not been explored within this population as opposed to the larger Black community.10,11 We conducted a detailed analysis of close social and sexual networks of Black MSM to determine the salient properties and components of these networks that are most related to HIV risk and preventive behavior among these men.