Trends in Online and In-Person Sex-Seeking Venues among Men who have Sex with Men in Berlin, Germany

Understanding sex-seeking venues used by men who have sex with men (MSM) may facilitate better study recruitment. We examined online and in-person sex-seeking venues among Berlin MSM. We enrolled participants with and without HIV receiving care in Berlin, Germany between 2018 and 2023. Participants completed a socio-behavioral questionnaire every six months for up to 24 months. Kruskal-Wallis tests and Joinpoint regression models were fitted to examine trends in use of sex-seeking venues. Robust Poisson regression models with generalized estimating equations were fitted to estimate adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs) for associations between characteristics and online sex-seeking. Of 285 visits among 126 MSM, sex-seeking via online venues was reported at 225 (78.9%) visits and via in-person venues at 185 (64.9%) visits. Grindr (66.0%) and Gayromeo (58.9%) were the most common online venues; clubs (42.9%) and parties (33.7%) were the most common in-person venues. Online sex-seeking was associated with sex under the influence of drugs (aPR [95% CI]; 1.26 [1.13, 1.41]), increasing numbers of sex partners (6-24: 1.59 [1.36, 1.86]; ≥25: 1.63 [1.38, 1.93]; compared to 1-5 partners), inconsistent condom use during receptive anal sex (2.15 [1.26, 3.65]), and being in a non-committed (4.94 [2.37, 10.29]) or non-monogamous (4.62 [2.29, 9.33]) relationship. Our findings suggest that venues that had been popular a few years ago may not be effective channels for study recruitment. Commonly used sex-seeking apps may be useful venues for studies to recruit participants to test HIV prevention, diagnosis, and treatment interventions.