Assessing the longitudinal stability of latent classes of substance use among gay, bisexual, and other men who have sex with men




Card, Kiffer G.
Armstrong, Heather L.
Carter, Allison
Cui, Zishan
Zhu, Julia
Lachowsky, Nathan J.
Moore, David M.
Hogg, Robert S.
Roth, Eric A.
Wang, Lu

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Drug and Alcohol Dependence


Background: Association between substance use and HIV-risk among gay and bisexual men (GBM) is well documented. However, their substance use patterns are diverse, and it is unknown whether self-reported use patterns are stable over time. Methods: Sexually-active GBM, aged >16 years, were recruited in Metro Vancouver using respondent-driven sampling and followed across 5 study visits at six-month intervals (n=449). To identify distinct patterns of substance use and their longitudinal stability, Latent Transition Analysis (LTA) was conducted for drugs reported by at least 30 participants. Intraclass correlation coefficients (ICC) quantified the stability of class assignments. Results: Six classes characterizing ‘limited drug use’ (i.e., low use of all drugs, except alcohol), ‘conventional drug use’ (i.e., use of alcohol, marijuana, and tobacco), ‘club drug use’ (i.e., use of alcohol, cocaine, and psychedelics), ‘sex drug use’ (i.e., use of alcohol, crystal meth, GHB, poppers, and erectile dysfunction drugs), ‘street drug use’ (i.e., use of alcohol and street opioids) and ‘assorted drug use’ (i.e., use of most drugs) were identified. Across five visits (2.5 years), 26.3% (n=118/449) of GBM transitioned between classes. The prevalence of limited use trended upwards (Baseline:24.5%, Visit 5:28.3%, p<0.0001) and assorted use trended downwards (13.4% to 9.6%, p=0.001). All classes had strong longitudinal stability (ICC>0.97). Conclusion: Stability of latent substance use patterns highlight the reliability of these measures in identifying patterns of substance use among people who use drugs – potentially allowing for better assessment of these groups and interventions related to their health.


The authors would like to thank the Momentum Health Study participants, office staff and community advisory board, as well as our community partner agencies, Health Initiative for Men, YouthCO HIV & Hep C Society, and Positive Living Society of BC.


Latent Transition Analysis, Substance Use, Gay and Bisexual Men


Card, K. G., Armstrong, H. L., Carter, A., Cui, Z., Wang, L., Zhu, J., Lachowsky, N. J., Moore, D. M., Hogg, R. S., & Roth, E. A. (2018). “Assessing the Longitudinal Stability of Latent Classes of Substance Use Among Gay, Bisexual, and Other Men Who Have Sex With Men.” Drug and Alcohol Dependence, 188, 348-355.