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Sexual risk behavior among HIV-uninfected men who have sex with men (MSM) participating in a tenofovir pre-exposure prophylaxis (PrEP) randomized trial in the United States.


Liu AY, Vittinghoff E, Chillag K, Mayer K, Thompson M, Grohskopf L, Colfax G, Pathak S, Gvetadze R, O'Hara B, Collins B, Ackers M, Paxton L, Buchbinder SP.

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OBJECTIVE:: To evaluate for changes in sexual behaviors associated with daily pill-use among MSM participating in a PrEP trial. DESIGN:: Randomized, double-blind, placebo-controlled trial. Participants were randomized 1:1:1:1 to receive tenofovir disoproxil fumarate or placebo at enrollment or after a 9-month delay and followed for 24 months. METHODS:: 400 HIV-negative MSM reporting anal sex with a man in the past 12 months and meeting other eligibility criteria enrolled in San Francisco, Atlanta, and Boston. Sexual risk was assessed at baseline and quarterly visits using Audio Computer-Assisted Self-Interview. The association of pill-taking with sexual behavior was evaluated using logistic and negative-binomial regression for repeated measures. RESULTS:: Overall indices of behavioral risk declined or remained stable during follow-up. Mean numbers of partners and proportion reporting unprotected anal sex (UAS) declined during follow-up (p<0.05), and mean UAS episodes remained stable. During the initial 9 months, changes in risk practices were similar in the group that began pills immediately vs. those in the delayed arm. These indices of risk did not differ significantly after initiation of pill-use in the delayed arm or continuation of study medication in the immediate arm. Use of poppers, amphetamines, and sexual performance-enhancing drugs were independently associated with one or more indices of sexual risk. CONCLUSIONS:: There was no evidence of risk compensation among HIV-uninfected MSM in this clinical trial. Monitoring for risk compensation should continue now that PrEP has been shown to be efficacious in MSM and other populations and will be provided in open-label trials and other contexts.




Adherence; Behavior; MSM; Novel Technologies


Created at 4/26/2013 11:44 AM by Davis, Gregory P
Last modified at 4/26/2013 11:44 AM by Davis, Gregory P