To compare demographic characteristics, sexual practices, unprotected receptive and insertive anal intercourse, substance use and rates of HIV-1 seroconversion between two prospective cohorts of HIV-negative men who have sex with men.
Comparative analysis of two independent cohorts.
Between May 1995 and April 1996, 235 HIV-negative Vanguard Project (VP) participants were enrolled and between January and December 1985, 263 HIV-negative participants in the Vancouver Lymphadenopathy AIDS Study (VLAS) completed a follow-up visit. The VP participants were compared with VLAS participants with respect to self-reported demographic variables, sexual behaviors, unprotected sex, substance use and rates of HIV-1 seroconversion during follow-up.
In comparison with the VLAS participants the VP participants were younger (median age, 26 versus 34 years; P