research methods

Sexuality Research and Social Policy, 2026 (doi:10.1007/s13178-026-01288-8).

Authors: Liana Aphami, Tamás Bereczky, Jules L Casalini, Nikolay Lunchenkov, Ulrich Marcus, Kai J Jonas, Axel J Schmidt.

Abstract

Introduction. Men-who-have-sex-with-men (MSM), as well as transgender and non-binary individuals, continue to face a disproportionate burden of stigma, mental health challenges, HIV, and other sexually transmitted infections. To address their needs, public health planners require reliable and comparable data. Monitoring behaviours in these populations also supports the evaluation of health policies.

Methods. The European-MSM-Internet-Survey (EMIS-2024) builds on our international surveys conducted in 2010 and 2017, expanding its scope to include explicitly transgender women and non-binary people. It provides much-needed data for planning interventions, promoting health, and harmonising behavioural surveillance. A key strength of EMIS-2024 is the use of a shared sampling frame and a core questionnaire across all participating countries. This approach allows meaningful cross-national comparisons, unlike many national surveys with varying methods. The three core consortium partners (Deutsche Aidshilfe, Robert Koch Institute and Maastricht University) led the revision of the EMIS-2017 questionnaire.

Results. Over 60 partners from 40 countries played a key role in the survey’s success, providing high-quality translations in 35 languages and actively promoting the survey. National partners ensured the survey’s visibility, credibility, and relevance once dating app advertisements or invitations appeared. The survey ran online during the first half of 2024. Overall, 165,380 responses were received, of which 50,330 qualified for the analytic sample.

Conclusions and Policy Implications. EMIS-2024 demonstrates that large-scale, multi-country sexual health surveys are feasible with public funding. A harmonised questionnaire, shared sampling strategy, and meaningful community involvement were key to generating robust, comparable data across Europe.

Country groupings used in EMIS-2024. For analytical purposes in the methods paper, countries are grouped as follows. We suggest this structure as a useful framework for international comparative analyses and journal articles:

EEA: Countries of the European Economic Area.
Non-EEA Advanced Economies: High-income countries outside the EEA within the WHO European Region (including Switzerland, Israel, and the United Kingdom), based on the International Monetary Fund (IMF) classification of advanced economies.¹
Western Balkans & Türkiye: Non-EEA countries in south-eastern Europe.
Eastern Europe and Central Asia (EECA): Non-EEA countries of the former Soviet Union.

This grouping facilitates epidemiological interpretation and comparability of trends across countries with markedly different economic conditions and epidemiological profiles. The grouping also reflects differences in study coordination and funding arrangements across participating countries and regions.

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Suggested citation:

Aphami L, Bereczky T, Casalini JL, Lunchenkov N, Marcus U, Jonas KJ, Schmidt AJ. European Men-Who-Have-Sex-With-Men and Trans People Internet Survey (EMIS-2024): Design and Methods. Sex Res Soc Policy (2026). https://doi.org/10.1007/s13178-026-01288-8

“Advanced economies” follow the International Monetary Fund’s World Economic Outlook country classification (International Monetary Fund, World Economic Outlook Database: Country Composition of WEO Groups). Alternatively, the term “non-EEA high-income countries” may be used to distinguish between EEA and non-EEA high-income countries, based on the World Bank country classification (World Bank. World Bank Country and Lending Groups). ↩︎

BMC Med Res Methodol 22, 59 (2022). https://doi.org/10.1186/s12874-021-01483-8

Authors: Ana Mendez‑Lopez, Ford Hickson, Klaus Jansen, Nathan Lachowsky, Fiona Burns, Cinta Folch, Annie Velter, Peter Weatherburn, Ulrich Marcus , Ursula von Rüden, Massimo Mirandola, Lorenzo Gios, Jamie Frankis, David J. Brennan and Axel J. Schmidt

Abstract

Background: To provide empirically based guidance for substituting partner number categories in large MSM surveys with mean numbers of sexual and condomless anal intercourse (CAI) partners in a secondary analysis of survey data.

Methods: We collated data on numbers of sexual and CAI partners reported in a continuous scale (write-in number) in thirteen MSM surveys on sexual health and behaviour across 17 countries. Pooled descriptive statistics for the number of sexual and CAI partners during the last twelve (N = 55,180) and 6 months (N = 31,759) were calculated for two sets of categories commonly used in reporting numbers of sexual partners in sexual behaviour surveys.

Results: The pooled mean number of partners in the previous 12 months for the total sample was 15.8 partners (SD = 36.6), while the median number of partners was 5 (IQR = 2–15). Means for number of partners in the previous 12 months for the first set of categories were: 16.4 for 11–20 partners (SD = 3.3); 27.8 for 21–30 (SD = 2.8); 38.6 for 31–40 (SD = 2.4); 49.6 for 41–50 (SD = 1.5); and 128.2 for ‘more than 50’ (SD = 98.1). Alternative upper cut-offs: 43.4 for ‘more than 10’ (SD = 57.7); 65.3 for ‘more than 20’ (SD = 70.3). Self-reported partner numbers for both time frames consistently exceeded 200 or 300. While there was substantial variation of overall means across surveys, the means for all chosen categories were very similar. Partner numbers above nine mainly clustered at multiples of tens, regardless of the selected time frame. The overall means for CAI partners were lower than those for sexual partners; however, such difference was completely absent from all categories beyond ten sexual and CAI partners.

Conclusions: Clustering of reported partner numbers confirm common MSM sexual behaviour surveys’ questionnaire piloting feedback indicating that responses to numbers of sexual partners beyond 10 are best guesses rather than precise counts, but large partner numbers above typical upper cut-offs are common.

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