The effectiveness of behavioural and psychosocial HIV/STI prevention interventions for MSM in Europe: A systematic review.

Given the need of programme planners and policy makers for descriptions of specific interventions and quantitative estimates of intervention effects to make informed decisions concerning prevention funding and research, there is a need for a systematic review that updates the current knowledge base about HIV/STI preventive interventions targeted at men who have sex with men (MSM) in Europe. The aim was to summarise and assess the effectiveness of HIV/STI prevention interventions for MSM living in Europe, and to identify intervention characteristics associated with effectiveness as well as potential gaps in the evidence base. A systematic search for relevant literature in eight international databases and in reference lists of relevant reviews and included studies was performed. Studies were selected according to pre-specified criteria and appraised for risk of bias. We summarised results using tables and calculated effect estimates for sexual behaviour outcomes. Results from six controlled studies, involving a total of 4,111 participants at entry from four different European countries were summarised. The results showed that there was 'high' or 'unclear' risk of bias in one or more of the assessed domains in all studies. The pooled effect estimate of the four interventions for which data were available suggested that MSM who participate in HIV/STI prevention initiatives may be somewhat less likely to report unprotected anal intercourse (UAI). The evidence base was insufficient to examine characteristics of interventions most closely associated with magnitude of effect and to draw solid conclusions about unique gaps in the evaluation literature. Despite the maturity of the HIV epidemic, rigorous outcome evaluations of any form of behavioural HIV/STI intervention for MSM in Europe are scarce. The results point to possible short term effects of interventions in terms of reductions in the proportion of MSM who engage in UAI, but the paucity of controlled studies demonstrates the need for research in this area. There is an overall deficit in outcome evaluations of interventions aimed at reducing HIV/STI risk behaviour among MSM in Europe. Designing behavioural HIV/STI preventive strategies to avert new infections, and the evaluation of such prevention programmes for MSM is an important component of a comprehensive HIV/STI containment strategy across the continuum of prevention and care.