Social networks and mortality based on the Komo-Ise cohort study in Japan.

Background: No prospective studies have examined the association between social networks and all-cause and cause-specific mortality among middle-aged Japanese. The study of varied populations may contribute to clarifying the robustness of the observed effects of social networks and extend their generalizability.

Methods: To clarify the association between social networks and mortality among middle-aged and elderly Japanese, a community-based prospective study, the Komo-Ise Study, was conducted in two areas of Gunma Prefecture, Japan.