NHBS Among Persons Who Inject Drugs (NHBS-PWID)

Persons who inject drugs (PWID) are at high risk for HIV through sharing needles, syringes, or other drug injection equipment, or sexual contact. In Colorado, approximately 8% of new HIV diagnoses are attributed to injection drug use. NHBS-PWID collects information on persons who report injecting a drug that was not prescribed for them in the 12 months before interview.

Before each NHBS cycle, formative assessment is conducted to learn more about the current status of the population and to inform operational procedures. Respondent-driven sampling (RDS) is used during the PWID cycles. A small number of initial participants, or “seeds,” are selected to complete the survey and recruit their peers to participate. Recruitment and referral 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 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.

PWID Cycles in Denver

PWID1 2006 PWID2 2009 PWID3 2012 PWID4 2015 PWID5 2018 PWID6 2022 PWID7 2024
Total completed surveys 519 430 516 603 595 283  
Total HIV tests -- 429 515 603 589 281  
HIV prevalence -- 4.7% 6.0% 4.5% 2.4% 5.7%  

Links to Reports