Methods
REGRESSIONS
Data come from a randomized controlled trial of a social network intervention targeting people who inject drugs in Ukraine (N = 1195). Indexes, plus two of their injection network members, received HIV testing and counseling (control arm) or HIV testing and counseling plus a social network intervention (intervention arm), in which indexes were trained to influence network members’ risk behaviors. We used Cox regressions with interaction terms to assess differences in time to HIV seroconversion between arms by network gender composition and gender of the index. For significant interaction terms, we calculated simple effects, generated survival functions using Kaplan–Meier methods, and compared survival curves using log-rank tests.