Objective To quantify the effect of opiate substitution treatment in relation to HIV transmission among people who inject drugs.Design Systematic review and meta-analysis of prospective published and unpublished observational studies.Data sources Search of Medline, Embase, PsychINFO, and the Cochrane Library from the earliest year to 2011 without language restriction. Review methodsWe selected studies that directly assessed the impact of opiate substitution treatment in relation to incidence of HIV and studies that assessed incidence of HIV in people who inject drugs and that might have collected data regarding exposure to opiate substitution treatment but not have reported it. Authors of these studies were contacted. Data were extracted by two reviewers and pooled in a meta-analysis with a random effects model. ResultsTwelve published studies that examined the impact of opiate substitution treatment on HIV transmission met criteria for inclusion, and unpublished data were obtained from three additional studies. All included studies examined methadone maintenance treatment. Data from nine of these studies could be pooled, including 819 incident HIV infections over 23 608 person years of follow-up. Opiate substitution treatment was associated with a 54% reduction in risk of HIV infection among people who inject drugs (rate ratio 0.46, 95% confidence interval 0.32 to 0.67; P<0.001). There was evidence of heterogeneity between studies (I 2 =60%, χ 2 =20.12, P=0.010), which could not be explained by geographical region, site of recruitment, or the provision of incentives. There was weak evidence for greater benefit associated with longer duration of exposure to opiate substitution treatment. ConclusionOpiate substitution treatment provided as maintenance therapy is associated with a reduction in the risk of HIV infection among people who inject drugs. These findings, however, could reflect comparatively high levels of motivation to change behaviour and reduce injecting risk behaviour among people who inject drugs who are receiving opiate substitution treatment.

HIV risk behaviors, susceptibility to HIV acquisition, progression of disease after infection, and response to anti-retroviral therapy all vary by age. In those living with HIV, current effective treatment has increased the median life expectancy to > 70 years of age. Biologic, medical, individual social and societal issues change as one ages with HIV infection, but there has been only a small amount of research in this field. Therefore, the Office of AIDS Research of the National Institutes of Health commissioned a working group to develop an outline of the current state of knowledge and areas of critical need for research in HIV and Aging; the working groups’ findings and recommendations are summarized in this report. Key overarching themes identified by the group included: multi-morbidity, poly-pharmacy and the need to emphasize maintenance of function; the complexity of assessing HIV vs. treatment effects vs. aging vs. concurrent disease; the inter-related mechanisms of immune senescence, inflammation and hypercoagulability; the utility of multi-variable indices for predicting outcomes; a need to emphasize human studies to account for complexity; and a required focus on issues of community support, caregivers and systems infrastructure. Critical resources are needed to enact this research agenda and include expanded review panel expertise in aging, functional measures and multi-morbidity, as well as facilitated use and continued funding to allow long-term follow-up of cohorts aging with HIV.

This study examined the reliability and validity of the Risk Behavior Assessment, a structured interview questionnaire designed to evaluate drug use and sexual HIV risk behaviors. Participants were 218 drug users currently not in treatment who completed the RBA two times over a 48-hour period and gave urine samples on both occasions. We examined internal consistency and test-retest reliability and found that, overall, drug users reliably report drug use and sexual behavior, although the reliability of reports of specific needle practice and sexual behavior items was somewhat lower. Validity results indicated that drug users' accurately report use of cocaine and opiates. These findings indicate that this self-report questionnaire, when administered by trained interviewers, reliably measures HIV risk behaviors in a drug-using population and provides a valid assessment of recent drug use.

From 1988 to 1991, 6,882 drug injectors in 15 US cities were interviewed and had serum samples collected. The interviews and samples were analyzed for determination of significant predictors of human immunodeficiency virus (HIV) seroconversion in the 10 low seroprevalence cities and the five high seroprevalence cities. The unit of analysis was the period of observation between consecutive paired interviews/blood samples. In Cox proportional hazards regression, significant predictors of seroconversion in the low seroprevalence cities were: not being in drug treatment, injecting in outdoor settings or abandoned buildings, using crack cocaine weekly or more frequently, engaging in woman-to-woman sex, being of non-Latino race/ethnicity, and city seroprevalence. Predictors in high seroprevalence cities were: injecting with potentially infected syringes, not being in drug treatment, and having a sex partner who injected drugs. These findings suggest that HIV may be concentrated in sociobehavioral pockets of infection in low seroprevalence cities. For reducing HIV transmission, these results suggest: 1) in low seroprevalence cities, localized monitoring to detect specific emerging sociobehavioral pockets of infection, and quick implementation of appropriate targeted interventions if necessary; 2) in high seroprevalence cities, relatively more emphasis on locality-wide outreach and syringe-exchange projects to reduce risky behavior; and 3) in both types of cities, considerable expansion of drug treatment programs.