Gay, bisexual, and other men who have sex with men (MSM) are disproportionately affected by HIV. In Colorado, approximately 60% of new HIV diagnosis are attributed to male-male sex with an additional 8% attributable to both male-male sex and injection drug use. NHBS-MSM collects information on persons who report sex with a male partner in the 12 months before the interview.
Before each NHBS cycle, formative assessment is conducted to learn more about the current status of the population and to inform operational procedures. Venue-based, time-space sampling (VBS) is used during the MSM cycles. Venues frequented by MSM (e.g., bars, clubs, organizations, and street locations) as well as days/times when men frequent those venues are identified. Venues for recruitment are chosen randomly each month.
Trained interviewers in all NHBS project areas use a standardized, anonymous questionnaire to collect information on HIV-related risk behaviors, HIV testing, and the use of HIV prevention services. HIV testing is offered to all participants regardless of their self-reported HIV status. During each cycle, a minimum of 500 eligible persons from each participating project area are interviewed and offered HIV testing.
MSM Cycles in Denver
| MSM1 2005 | MSM2 2008 | MSM3 2011 | MSM4 2014 | MSM5 2017 | MSM6 2021* | MSM7 2023 | |
|---|---|---|---|---|---|---|---|
| Total completed surveys | 869 | 545 | 547 | 528 | 533 | 91 | 475 |
| Total HIV tests | -- | 479 | 507 | 496 | 524 | 19 | 462 |
| HIV prevalence | -- | 15.9% | 16.2% | 15.5% | 12% | 20% | 10% |
Note: Respondent-driven sampling was piloted during the 2021 MSM cycle because venues were not accessible due to the COVID-19 pandemic.