Predictors and correlates of reduced frequency or cessation of injection drug use during a randomized HIV prevention intervention trial.

AIMS: This study conducted a secondary analysis to examine injection cessation and decreasing frequency of injection during a multi-site randomized controlled HIV prevention intervention trial that sought to reduce sexual and injection risk behavior among young injection drug users.

DESIGN AND SETTING: A six-session, cognitive-behavioral skills-building intervention in which participants were taught peer education skills [peer education intervention (PEI)] was compared with a time-equivalent attention control. Follow-up interviews were conducted at 3 and 6 months post-baseline.

PARTICIPANTS: Trial participants were HIV and hepatitis C virus (HCV) antibody-negative injection drug users aged 15-30 years. Participants who had at least one follow-up interview and reported injecting drugs in the previous 3 months at baseline were eligible for the present analysis (n = 690).

MEASUREMENTS: At each interview, data were collected on the number of times participants injected drugs over the previous 3 months.

FINDINGS: Twenty-seven per cent of participants reported at least one 3-month period of injection cessation. In a multivariate, zero-inflated negative binomial regression adjusting for prior injection frequency, time of follow-up and psychosocial variables, PEI trial arm and smaller session size were associated significantly with injection cessation. Trial arm had no effect on the frequency of injection among those who continued to inject.

CONCLUSIONS: HIV prevention interventions that encourage injection drug users to take on the role of peer educator may have the additional benefit of increasing the likelihood of injection cessation. Intervention group size is also an important consideration, with smaller groups having higher rates of cessation.