National HIV Behavioral Surveillance System (NHBS)

NHBS is part of the US Center for Disease Control’s (CDC) national study of risk behaviors among high-risk groups.

Each year the CDC establishes a priority population whose risk behaviors they would like to study. AIDS Action staff members recruit people from the target population and conduct individual interviews to gather data regarding behavioral patterns. Stipends are provided to survey participants.

In 2003, CDC created NHBS to conduct behavioral surveillance among persons at high risk for HIV infection. Surveillance is conducted in rotating, annual cycles in three different populations at increased risk for HIV:

  • Gay, bisexual and other men who have sex with men; known as the MSM cycle.
  • Persons who inject drugs (PWID); known as the injection drug use or IDU cycle, and
  • Heterosexuals at increased risk for HIV infection; known as the HET cycle.

Before each NHBS cycle, formative assessment is conducted to learn more about each local population and to inform operational procedures. Venue-based, time-space sampling (VBS) is used during the MSM cycles. Health department staff identify venues frequented by MSM (e.g., bars, clubs, organizations, and street locations) as well as days/times when men frequent those venues. Venues (and specific day/time periods) for recruitment are chosen randomly each month. Respondent-driven sampling (RDS) is used during the IDU and HET cycles. Health department staff select a small number of initial participants, or “seeds,” who complete the survey and recruit their peers to participate. Recruitment and interviewing then continue until the target sample size is reached.

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. During each cycle, a minimum of 500 eligible persons from each participating project area are interviewed and offered HIV testing.

For more information about NHBS, visit the CDC online or call our main number at 617.437.6200.