Injecting drug use in sexual settings (‘slamsex’) among gay, bisexual and other men who have sex with men in Taiwan: patterns, predictors and potential for harm reduction

The intersection of chemsex and injecting drug use, slamsex, raises concern about human immunodeficiency virus (HIV) acquisition, sexually transmitted infections and psychological distress. Given the lack of local evidence to guide harm reduction, this study explored factors and harms associated with slamsex among gay, bisexual and other men who have sex with men (GBMSM) in Taiwan. The Chemsex Online Survey for Men who Have Sex with Men in Taiwan (COMeT) was a cross-sectional study conducted from December 2018 to January 2019. Taiwanese adult GBMSM who report chemsex in the past twelve months were recruited online. The survey collected data on sociodemographics, sexual and drug use behaviours, experienced harm, and harm reduction measures. Multivariable logistic regression analyses were utilised to assess factors associated with injecting drug use. Among 515 participants surveyed, most were under 39 years (84.5%) and living with HIV (54.8%); nearly one-quarter reported slamsex in the past six months. In multivariable analysis, slamming was associated with polysubstance use during chemsex (aOR 3.28, 95% CI: 1.31, 8.20), higher number of sexual partners (aOR 2.27, 95% CI; 1.0, 5.17), hepatitis C infection history (aOR 2.62, 95% CI; 1.17, 5.85), and methamphetamine dependency (aOR 1.69, 95% CI; 1.05, 2.71). Injecting participants reported more physical, psychological, social and legal harms. Common harm reduction strategies included smoking instead of injecting, maintaining rest, nutrition, hydration, avoiding concurrent alcohol, and not sharing needles. Slamsex among Taiwanese GBMSM is associated with elevated sexual risk, mental, and social harms, highlighting the need for integrated, community-informed harm reduction and policy reform.