Delineating patterns of sexualized substance use and its association with sexual and mental health outcomes among young gay, bisexual and other men who have sex with men in Singapore: a latent class analysis

BACKGROUND: Young gay, bisexual, and other men who have sex with men (YMSM) are vulnerable to the risks associated with sexualized substance use. This is a novel study in Singapore that aims to classify patterns of sexualized substance use among YMSM, and investigate its association with sexual and mental health outcomes. METHODS: In this cross-sectional study among 570 YMSM aged 18 to 25 years old, latent class analysis (LCA) conducted to identify classes with similar patterns of sexualized substance use, across which measures of inconsistent condom use, recent STI diagnoses, past suicide ideation and depression severity were compared. RESULTS: LCA revealed three classes of YMSM based on types of substances ever used in sexualized contexts, which we labelled as ‘substance-naive’, ‘substance-novice’, and ‘chemsex’. Substance-naive participants (n = 404) had only ever used alcohol, while substance-novice participants (n = 143) were primarily amyl nitrite users with a small proportion who reported using chemsex-related drugs. Chemsex participants (n = 23) comprised individuals who had mostly used such drugs. Those in the chemsex group were more likely to report recent unprotected anal sex with casual partners (aPR = 3.28, 95%CI [1.85, 5.79]), depression severity (aβ = 3.69, 95%CI [0.87, 6.51]) and a history of suicide ideation (aPR = 1.64, 95%CI [1.33, 2.03]). CONCLUSIONS: Findings of this study highlight how the use of varying substances in sexualized contexts may be classified and characterized by different sexual and mental health outcomes. Health promotion efforts should be differentiated accordingly to address the risks associated with sexualized substance use among YMSM. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-021-11056-5.