Once the participant named five network members, information was gathered regarding demographics, characteristics of the relationship and interactions between the participant and the network members. Networks were generated by asking each participant to indicate individuals who were known to them socially, sexually or as people they took drugs with. There was a much larger percentage of HIV-positive black MSM (32%) than either Latino (13%) or white MSM (2%) in the cohort. Of the cohort, 49% indicated some college education, with a higher percentage of white MSM indicating this (59%).Ī higher percentage of black MSM indicated bisexuality as a sexual preference when compared with white MSM (26% vs 10%). All of the 1015 participants were aged 16-29, with 34% identifying as black, 30% as Latino, 25% as white and 11% as other. Researchers used community sampling, drawing on partner and peer connections when recruiting participants. Factors such as homophily (the likelihood of having a same-race sexual partner) and density of networks may play a crucial role in HIV transmission. As well as individual factors, the authors took a network approach, involving measures of sexual connectedness within networks which could possibly account for higher HIV rates among black YMSM. This cohort study with young men who have sex with men (YMSM) in Chicago explored the effects of networks on HIV transmission in order to explain the racial disparities in HIV rates among MSM in the US.