More than half of respondents had used poppers at any time, 18% had used them during receptive UAI, and 8% had used them during receptive UAI with a man they did not know to be HIV-negative. These questions were asked because previous research has identified using poppers during receptive unprotected anal intercourse (UAI) with an HIV-positive partner to be a significant factor that facilitates HIV transmission. The survey asked a number of questions about the use of the recreational drug poppers during sex. Groups showing particularly low levels of knowledge on this topic were those who had never tested for HIV, younger men, men with less formal education, and men with fewer sexual partners.