Resum
This study describes the prevalence of anabolic-androgenic steroid (AAS) injection, their
main correlates, and the prevalence of specific AAS injection risk behaviours among men who
have sex with men (MSM), an area insufficiently addressed in scientific research. Participants were
HIV-negative MSM attending four HIV/STI diagnosis services: two clinics and two community
programmes in Madrid and Barcelona. Participants answered an online self-administered ques-
tionnaire. Crude and adjusted lifetime prevalence and prevalence ratios (PRs) were calculated by
different factors and using Poisson regression models with robust variance. Of the 3510 participants,
6.1% (95% CI: 5.3–6.9) had injected AAS before and 3.5% (95% CI: 2.9–4.2) had done so in the last
12 months. In the multivariate analysis, AAS injection was independently associated with being over
40 years old (aPR = 3.6; 95% CI: 2.0–6.5) and being born in Latin America (aPR = 2.5; 95% CI:1.9–3.4),
and was less strongly associated (aPRs of around two) with having been recruited into STI clinics,
having ever been paid for sex before, injected drugs, used drugs for sex, having been diagnosed
with an STI before, and having been diagnosed with HIV at the recruitment consultation. Only
three participants, 1.4%, of those who had injected AAS before had shared AAS or equipment for
preparation or injecting before. Conclusions: In contrast to drugs, AAS injecting behaviours do not
play a relevant, direct role in the transmission of blood-borne infections among MSM. However, AAS
injectors have a higher prevalence of sexual risk behaviours. These findings should be confirmed
using new studies that employ other sampling procedures.