This study assessed the knowledge and prior use of HIV self-testing in a sample of men who have sex with men (MSM) recruited in a sexual health clinic and two community-based testing sites in Madrid and Barcelona, >12 months after its legal authorization. Between March 2019 and December 2020, we recruited 2044 MSM. Participants completed a self-administered questionnaire while waiting to be tested for HIV and other STIs. We built two Poisson regression models to assess factors associated with prior knowledge and with use. Among those who had used self-testing in the past we assessed frequency of use and several aspects related to the last testing episode. The proportion of participants that knew about the existence of self-testing and had already used it was of 26.3% and 5.1% respectively. Both, knowledge and use were independently associated with being born in Spain or other western European countries, university education and more recent HIV testing. Additionally, knowledge was associated with older age, having a more favorable economic situation, and not living sexuality in total secrecy. Use was also associated with having received money in exchange for sex. Most (69.5%) reported having self-tested once, 64.8% had self-tested <12 months ago, 63.8% self-tested alone and 71.4% acquired the kit at a pharmacy over the counter. In spite of its authorization and becoming legally available, knowledge and use of HIV self-testing remain low among MSM attending sites specialized in the diagnosis of HIV and other STIs. When designing scale-up strategies, lower levels of knowledge and use in less favored subgroups of MSM need to be factored in.
Keywords: HIV self-testing (HIVST); early diagnosis; men who have sex with men (MSM).