Social network and contextual influences on substance use and HIV risk behavior among young men who have sex with men

In the United States, men who have sex with men (MSM) remain the group most affected by HIV with younger men at particular risk for new infection. Venue-based HIV prevention shows promise in reducing the spread of HIV among young MSM (YMSM); however, little research has been conducted on the social contexts where YMSM congregate and engage in behaviors that promote HIV risk, such as substance use. Informed by Social Action Theory (Ewart, 1991), which emphasizes the importance of the social environment in influencing individual behavior and has been used to explain substance use and sexual risk behavior among YMSM previously, the present study examines YMSM socialization patterns and their association with substance use and sexual risk behavior. Participants (N=484) nominated their top three favorite places to socialize in Los Angeles, California; these affiliation data were transformed into two networks: one that connected YMSM through shared venue attendance (i.e., person network) and another that connected venues through co-nomination by YMSM (i.e., venue network). Social network analysis techniques were used to identify structural properties of both networks, which were then associated with substance use and sexual risk behavior of participants.;Over 100 venues were nominated as favorite places to socialize. Almost all participants (99%) were connected by at least one venue and over 80% were connected by two or more venues, indicating a high potential for social interaction among YMSM based on shared venue attendance. Nearly all venues in the center of the venue network were bars and dance clubs classified as "High-risk" by a Community Advisory Board. However, a few key coffee shops and restaurants classified as "Low-risk" were also central. The majority of YMSM indicated recent alcohol use (94%) and large percentages had smoked cigarettes (82%) and used marijuana (62%) in the past 3 months. Users of these commonly available substances were more central to the person network and were positioned next to other users more frequently than non-users were positioned next to non-users. Illicit substance users (29%) and club drug users (23%) were evenly dispersed throughout the person network and were more likely to be connected to non-users than other users. YMSM who had engaged in unprotected anal intercourse with serodiscordant or multiple partners in the past 3 months (26%) and those previously diagnosed with an STI (25%) were also dispersed throughout the person network.;YMSM in Los Angeles are highly interconnected based on their shared attendance at a core group of similar and geographically proximal venues. These findings indicate the potential utility of targeted, venue-based HIV prevention that can be diffused quickly to large numbers of YMSM who attend a core group of popular social venues. Highly shared "Low-risk" venues (e.g., coffee shops) may be particularly useful in staging primary HIV prevention interventions that can be disseminated by YMSM who cross over into more "High-risk" venues. Findings from the present research lend support to prior research on co-occurring health problems among YMSM and demonstrate the ways in which HIV-related risk behavior are concentrated in popular YMSM social contexts.