Evidence map›Paper›PMID 42740683›Full record

ArticleJournal of the International AIDS Society2026

Prevalence, Patterns and Implications of Chemsex Substance Use Among Gay and Bisexual Men Who Have Sex With Men: A Cohort-Collaboration Between the Swiss HIV Cohort Study and the SwissPrEPared Study.

Bashkim Jaha, Andrea Farnham, Roger Kouyos, Jan Fehr, Babette L Winter, Irene A Abela, Marcel Stöckle, Bernard Surial, Matteo Reymond, Matthias Cavassini and 5 more

Abstract read
In one paragraph

Article in Journal of the International AIDS Society, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

15 authors.

Bashkim JahaDivision of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland.ORCID https://orcid.org/0009-0005-4095-0152
Andrea FarnhamDepartment of Public & Global Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0002-0830-0927
Roger KouyosDivision of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0002-9220-8348
Jan FehrDepartment of Public & Global Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
Babette L WinterDepartment of Public & Global Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0001-8293-9844
Irene A AbelaDivision of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0002-5566-8628
Marcel StöckleDivision of Infectious Diseases & Hospital Epidemiology, University Hospital Basel, University of Basel, Basel, Switzerland.ORCID https://orcid.org/0000-0002-0088-5078
Bernard SurialDepartment of Infectious Diseases, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.ORCID https://orcid.org/0000-0002-1402-974X
Matteo ReymondDivision of Infectious Diseases, University Hospital Geneva, University of Geneva, Geneva, Switzerland.ORCID https://orcid.org/0009-0006-3032-8316
Matthias CavassiniDivision of Infectious Diseases, University Hospital Lausanne, University of Lausanne, Lausanne, Switzerland.ORCID https://orcid.org/0000-0003-0933-7833
David Jackson-PerryDivision of Infectious Diseases, University Hospital Lausanne, University of Lausanne, Lausanne, Switzerland.ORCID https://orcid.org/0000-0001-5889-1553
Luigia ElziDivision of Infectious Diseases, Ente Ospedaliero Cantonale, Lugano, Switzerland.
Julia NotterDivision of Infectious Diseases, Infection Prevention and Travel Medicine, Department General Internal Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.ORCID https://orcid.org/0000-0003-4821-9995
Benjamin HampelDepartment of Public & Global Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0002-5474-5927
Katharina KusejkoDivision of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland.ORCID https://orcid.org/0000-0002-4638-1940

Funding

Swiss Federal Office of Public Health 142006945/332.3-54/20Swiss National Science Foundation #218408Swiss National Science Foundation #33FI-0_229621
6 · The paper itself

Abstract

introductionGlobal awareness to chemsex, a specific form of sexualized psychoactive substance ("chems") use among gay, bisexual and other men who have sex with men (gbMSM), is increasing. We aimed to assess prevalence, patterns and implications of "chems" use on chemsex-related outcomes.

methodsWe conducted a Swiss-wide longitudinal study using individual-level data from April 2019 to December 2024 of adult gbMSM with HIV, enrolled in the Swiss HIV Cohort Study (SHCS), or taking HIV pre-exposure prophylaxis (PrEP), enrolled in SwissPrEPared. Determinants of "chems" (methamphetamine, new psychoactive stimulants, GHB/GBL) use and clinical implications were analysed using logistic regression. Longitudinal "chems" use patterns were distinguished by rule-based classification. Point-prevalences of "chems" use, including COVID-19 and mpox periods, were analysed using interrupted time series analysis.

resultsWe analysed 107,855 follow-up visits from 13,304 gbMSM. "Chems" were used by 17.2% of gbMSM (21.4% in SwissPrEPared vs. 11.2% in the SHCS). Age below 26 (compared to 26-37, adjusted odds ratio [aOR]: 0.82, 95%-confidence interval: 0.68-0.96), over 37 (aOR for 38-48: 0.84, 0.75-0.94; aOR for over 48: 0.54, 0.47-0.62) and bisexual orientation showed lower odds (aOR: 0.78, 0.66-0.90), while participation in French-speaking SwissPrEPared centres (aOR compared to SHCS Eastern Switzerland: 1.41, 1.22-1.64) and sex with non-steady partners showed higher odds for "chems" use (aOR: 12.44, 8.85-18.17). "Chems" use was associated with depression, inconsistent condom use, high non-steady partner count and sexually transmitted infections (STIs). Comparing longitudinal use patterns, temporally restricted use, that is, recovering from stable use, reported "chems" use only once, or for a single episode shorter than 1 year, showed the lowest risk for STIs and high partner count, whereas intermittent use showed lower risk only for syphilis. "Chems" use decreased marginally during COVID-19 and mpox, with a quick return and no difference to levels before COVID-19.

conclusionsA large proportion of gbMSM use "chems," with congruent determinants across both cohorts but heterogeneous impact on sexual and mental health that varies by specific substance and longitudinal use patterns. Further understanding of underlying mechanisms driving this heterogeneity is needed before delivering mechanism-informed interventions tailored to "chems" use patterns, like STI and depression screening, harm-reduction counselling and linkage to addiction care.

Indexed as

HIV InfectionsHomosexuality, MaleSexual and Gender MinoritiesSubstance-Related DisordersAdultBisexualityChemsexCOVID-19HumansLongitudinal StudiesMalePrevalenceSwitzerlandHIVlongitudinal analysisPrEPsexual behavioursexually transmitted diseasessubstance use

Identifiers

PMID42740683
PMCPMC13575759

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