Chemsex-related drug use and its association with health outcomes in men who have sex with men: a cross-sectional analysis of Antidote clinic service data.

PURPOSE: Chemsex-related drug use (CDU) is an escalating public health issue among men who have sex with men (MSM), associated with significant physical, biomedical and psychosocial harm. Few interventions exist to help MSM engaging in chemsex and little data exist on which to build. This cross-sectional analysis, using data from Antidote, the UK's only lesbian, gay, bisexual, and transgender specialist drug service, aims to remedy this paucity of data.
METHODS: Modified Poisson regression was used to assess associations between CDU and a range of health outcomes; CDU+ subanalysis disaggregated MSM by primary chemsex drug of concern; and HIV+ subanalysis investigated whether CDU was associated with self-reported treatment adherence, HIV seroconversion and other HIV-specific issues.
FINDINGS: Compared with CDU- MSM, MSM presenting for CDU were more likely to be HIV+, current or previous injectors, to have used postexposure prophylaxis in the last year, and have had ≥6 sexual partners in the last 90 days, though less likely to be hazardous alcohol consumers or to have experienced previous suicidal ideation (all p<0.0005). CDU+ subanalysis revealed health outcome differences-those selecting mephedrone were less likely to be hepatitis C+, HIV+, current or previous injectors, or to have experienced previous suicidal ideation (all p<0.0005), whereas those selecting methamphetamine were more likely (all p<0.0005, except suicidal ideation p=0.009). IMPLICATIONS: This analysis shows MSM presenting for CDU are a heterogeneous high-risk population with unmet health needs. There is a need for standardised chemsex surveillance and for improved intersectorial working between sexual health and drug treatment services. Future research should investigate typological differences between MSM presenting for CDU. ORIGINALITY/VALUE: To date, this is the world's largest analysis of MSM seeking treatment for CDU. Further, the publication of 'real-world' service data is a valuable addition to the literature alongside surveys and recruited studies. © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.