Combination HIV Prevention Strategies Among Montreal Gay, Bisexual, and Other Men Who Have Sex with Men in the PrEP Era: A Latent Class Analysis




Doyle, Carla M.
Maheu‑Giroux, Mathieu
Lambert, Gilles
Mishra, Sharmistha
Apelian, Herak
Messier‑Peet, Marc
Otis, Joanne
Grace, Daniel
Hart, Trevor A.
Moore, David M.

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AIDS and Behavior


Pre-exposure prophylaxis (PrEP) became publicly available in Quebec for gay, bisexual and other men who have sex with men (GBM) in 2013. We used baseline data from Engage, a cohort of GBM recruited by respondent-driven sampling, to examine patterns of combination HIV prevention use among Montreal GBM since PrEP became available. Latent class analysis, stratified by HIV status, was used to categorize GBM by self reported use of biomedical and behavioural prevention strategies. Correlates of resulting classes were identified using multinomial logistic regression. Among HIV-negative/ unknown GBM (n = 968), we identified four classes: low use of prevention (32%), condoms (40%), seroadaptive behaviour (21%), and biomedical (including PrEP; 7%). Those using prevention (condoms, seroadaptive behaviour, and biomedical) had a higher number of anal sex partners and were more likely to report a recent sexually transmitted infection diagnosis. GBM using biomedical prevention also had a higher level of formal education. Among GBM living with HIV (n = 200), we identified three classes: mainly antiretroviral treatment (ART) with viral suppression (53%), ART with viral suppression and condoms (19%), and ART with viral suppression and seroadaptive behaviour (18%). Again, the number of anal sex partners was higher among those using condoms and seroadaptive behaviours. Our findings show antiretroviral-based prevention, either alone or in combination with other strategies, is clearly a component of the HIV prevention landscape for GBM in Montreal. Nevertheless, PrEP uptake remains low, and there is a need to promote its availability more widely.


The authors would like to thank the Engage study participants, office staff, and community engagement committee members, as well as our community partner agencies REZO, ACCM and Maison Plein Coeur. The authors also wish to acknowledge the support of Jody Jollimore and their contribution(s) to the work presented here. Engage/Momentum II is funded by the Canadian Institutes for Health Research (CIHR, #TE2-138299), the CIHR Canadian HIV/AIDS Trials Network (#CTN300), the Canadian Foundation for AIDS Research (CANFAR, #Engage), the Ontario HIV Treatment Network (OHTN, #1051), the Public Health Agency of Canada (Ref: 4500370314), Canadian Blood Services (#MSM2017LP-OD), and the Ministère de la Santé et des Services sociaux (MSSS) du Québec. CMD is supported by Engage, Universities Without Walls (UWW) and the Fonds de recherche du Québec—Santé (FRQS). MMG acknowledges funding from the CANFAR, CIHR, and FRQS. Finally, the authors would like to thank the Quebec Population Health Research Network (QPHRN) for its contribution to the financing of this publication.


Combination HIV prevention, HIV prevention strategies, Men who have sex with men, Pre-exposure prophylaxis, Latent class analysis


Doyle, C. M., Maheu-Giroux, M., Lambert, G., Mishra, S., Apelian, H., Messier-Peet, M., Otis, J., Grace, D., Hart, T. A., Moore, D. M., Lachowsky, N. J., & Cox, J. (2021). “Combination HIV Prevention Strategies Among Montreal Gay, Bisexual, and Other Men Who Have Sex with Men in the PrEP Era: A Latent Class Analysis.” AIDS and Behavior, 25, 269-283. DOI: s10461-020-02965-4