RESUMO
Our aims were: (1) to characterize gay, bisexual and other men who have sex with men (GBMSM) and transgender (TG) populations using internet-based self-sampling services in the TESTATE project or attending community-based STI/HIV voluntary counselling and testing (CBVCT) services as alternative strategies to formal HIV testing within the Spanish national health system, and (2) to identify factors associated with repeat use of the same screening strategy from November 2018 to December 2021. Demographic, health, and behavioral characteristics of users using complementary strategies were analyzed. We developed a cross-sectional study, with descriptive analysis, HIV cascade, and a multivariate logistic model to identify factors associated with participants' repeated use of the same screening strategy. We included 9939 users, of whom 94.1% were GBMSM (n = 9348) and 5.9% TG (n = 580), with a high representation of migrants. Reactive results were 3.4% (n = 340), with 3.0% in GBMSM (n = 277/9348) and 10.7% in TG (n = 63/591). 73.8% (n = 251) were confirmed HIV positive and 76.7% (n = 194) were linked to health services. Users repeated the online screening strategy more than CBVCT (44.3% vs. 31.8%), but TG population used face-to-face community services more (8.4% vs. 0.6%). Factors influencing the repetition of the online self-sampling strategy included older age, non-migrant status, and recent HIV testing. In the CBVCT strategy, factors included older age, TG identity, non-migrant status, condom use during the last sexual encounter, and recent HIV testing. In conclusion, both CBVCT and online-requested self-sampling at home are important alternatives to the health system for the provision of HIV testing to GBMSM and TG.