An examination of users’ influence in online HIV/AIDS communities

A network perspective was adopted in this study to identify influential users in an online HIV community in China. Specifically, the indegree centrality, outdegree centrality, betweenness centrality, eigenvector centrality, and clustering coefficient of individuals were evaluated to measure the user influence in such a community. Moreover, this study examined how the digital divide, which is presently one of the major social equity issues in the information society, is associated with an individual's influence within the community. Two networks were formed on the basis of the behavioral data retrieved from the HIV community: the follower–followee network and the post-reply network. In the follower–followee network, members from areas with well-developed technologies demonstrated more connections, received more attention, and secured more critical positions in the network than their counterparts. However, such differences were insignificant in the post-reply network.

The rise of information and communication technologies (ICTs), particularly social networking sites (SNSs), has facilitated the production and dissemination of health-related information.1,2 Health communication professionals have used SNSs for health campaigns and promotions as well.3 Since the 1950s, scholars have argued that audiences usually receive information from influential individuals around them apart from directly obtaining information from mass media.4 Recently, Valente5 maintained that audiences do not receive health information in a vacuum; rather, they filter and interpret such information with other individuals in their social networks. These influential individuals in health campaigns have been termed as “interpersonal influencers,” who “are in a position to exercise means control as well as utilizing persuasion.”6(p283)

In health campaigns on SNSs, the influence of individual users is prominent for two reasons. First, individuals integrate their offline social networks into SNSs,7 thereby making interpersonal communication convenient and efficient. Second, user-generated content, such as comments and retweets, has become an indispensable part of health campaign messages on SNSs.8 Such user-generated content might strengthen the influence of certain users on other SNS users.8 Thus, the identification of potential interpersonal influencers on SNSs will provide health professionals with valuable information for designing and implementing health campaigns on SNSs. The purpose of this study is to identify influential users in an HIV/AIDS community on SNSs. Moreover, we examine how the digital divide, one of the major social equity issues in the current information society,9 is associated with an individual's influence in this community.