Chemsex Interventions for Men Who Have Sex With Men: A Systematic Review and Meta-Analysis.

Behavioural and pharmacological interventions aimed at reducing chemsex practices (the use of psychoactive drugs before or during sexual activity) have been introduced; however, the effectiveness of these interventions remains unclear. This systematic review aims to summarise the effectiveness of bio-behavioural chemsex interventions. PubMed and EMBASE databases were searched, without date and setting restrictions, for studies on chemsex interventions for men who have sex with men (MSM). Eligible studies were assessed, and data were extracted on primary outcomes (high-risk sexual behaviours) and secondary outcomes (sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) incidence, adherence to post-exposure prophylaxis after sexual exposure (PEPSE) and anti-retroviral therapy (ART)). The results were presented quantitatively through a meta-analysis. A total of twelve studies (1,711 participants) were included in the review, while nine studies (1,145 participants) contributed to the meta-analysis. Bio-behavioural chemsex interventions decreased the number of episodes of unprotected anal intercourse (UAI) with serodiscordant partners (MD: -1.30, 95% CI: -1.58 to -1.03; p<0.001). Interventions also decreased the total number of sexual partners and the number of partners where UAI was used, though not significantly. The use of psychoactive substances during sexual activities was not reduced among those who had interventions. Bio-behavioural chemsex interventions reduce the risk of UAI with serodiscordant partners, a high-risk factor for HIV seroconversion. More research is needed on other benefits of chemsex interventions.