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and unpublished observational studies.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 methods We 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.
Results Twelve 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unpublished data were obtained from three additional studies.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