The Healthy Young Men's Study: Sampling Methods to Recruit a Random Cohort of Young Men Who Have Sex with Men.

Recruiting a scientifically sound cohort of young men who have sex with men (YMSM) is an enduring research challenge. The few cohort studies that have been conducted to date on YMSM have relied on non-probability sampling methods to construct their cohorts. While these studies have provided valuable information about HIV risk behaviors among YMSM, their generalizability to broader YMSM populations is limited.In this paper the authors describe a venue-based sampling methodology used to recruit a large and diverse cohort of YMSM from public venues in Los Angeles County. Venue-based sampling is a multi-stage, probability sampling design that uses standard outreach techniques and standard survey methods to systematically enumerate, sample, and survey hard-to-reach populations. The study design allowed the authors to estimate individual, familial and interpersonal psychosocial factors associated with HIV risk and health seeking behaviors for a cohort of YMSM with known properties. Study participants completed an extensive baseline survey and over a two year period will complete four follow-up surveys at six-month intervals. The baseline survey was administered in both English and Spanish.