Abstract
BACKGROUND: The seating arrangement of in-center hemodialysis is conducive to patients forming a relationship and a social network. We examined how seating in the in-center hemodialysis clinic affected patients forming relationships, whether patients formed relationships with others who have similar transplant behaviors (homophily), and whether these relationships influenced patients (social contagion) to request a living donation from family and friends outside of the clinic. METHODS: In this 30-month, prospective cohort study, we observed the relationships of 46 patients on hemodialysis in a hemodialysis clinic. Repeated participant surveys assessed in-center transplant discussions and living-donor requests. A separable temporal exponential random graph model estimated how seating, demographics, in-center transplant discussions, and living-donor requests affected relationship formation via sociality and homophily. We examined whether donation requests spread via social contagion using a susceptibility-infected model. RESULTS: For every seat apart, the odds of participants forming a relationship decreased (OR, 0.74; 95% CI, 0.61 to 0.90; P=0.002). Those who requested a living donation tended to form relationships more than those who did not (sociality, OR, 1.6; 95% CI, 1.02 to 2.6; P=0.04). Participants who discussed transplantation in the center were more likely to form a relationship with another participant who discussed transplantation than with someone who did not discuss transplantation (homophily, OR, 1.9; 95% CI, 1.03 to 3.5; P=0.04). Five of the 36 susceptible participants made a request after forming a relationship with another patient. CONCLUSIONS: Participants formed relationships with those they sat next to and had similar transplant behaviors. The observed increase in in-center transplant discussions and living-donation requests by the members of the hemodialysis-clinic social network was not because of social contagion. Instead, participants who requested a living donation were more social, formed more relationships within the clinic, and discussed transplantation with each other as a function of health-behavior homophily.