An exponential random graph modeling of patient-to-patient interactions on social media

To understand the interactions among people living with HIV/AIDS (PLWHA), the study maps the topology of patient-to-patient interactions on SNSs and examines the roles of two tie-generation mechanisms (i.e., homophily and preferential attachment) underlying such interaction structure. The study decomposes patient-to-patient interactions into two ways: passive interaction by paying attention to peers’ up-to-date status and active interaction by directly communicating with peers on SNSs. The results show that the PLWHA’s attention and communication networks are small world characterized by small diameters and large clustering coefficients. Homophily and preferential attachment mechanisms play different roles in tie-generation of these two networks. Specifically, PLWHA are likely to pay attention to peers who are similar to them in terms of location, membership, and concern, and follow those influential peers on SNSs. However, they prefer to directly communicate with peers who share the same membership and concern, and avoid communicating with influential peers on SNSs.