Abstract Body

There has been increasing traditional and social media coverage of pre-exposure prophylaxis using combination emtricitabine/tenofovir (FTC/TDF) to prevent HIV infection (PrEP). We sought to describe changes in awareness of PrEP, willingness to use PrEP, and use of PrEP among internet-using men who have sex with men (MSM) from the time before FDA-approval of FTC/TDF for PrEP in July 2012 through March 2015.

Data were from 3 nationwide cross-sectional internet surveys of MSM living in the United States. The analysis sample included men who reported sex with a man in the past 12 months and did not report being HIV-positive. Because the percentage reporting awareness of PrEP changed non-linearly over time within survey cycle, we aggregated data into groups of months that spanned cycles to perform a segmented regression assessing the time trend for percentages of participants reporting awareness of, willingness to use, and actual use of PrEP.  Multivariate models controlled for source of recruitment (a geo-location based sexual networking site versus other websites), race, educational attainment, income and risk behaviors included as indicators for PrEP in CDC guidelines (≥10 partners vs. ≤9, and bacterial STI diagnosis in the prior 12 months.) For awareness and use of PrEP we used a Poisson risk model with 3 indicator variables for time (See Table). We used a log-binomial model of percentage willing to use PrEP because the Poisson model gave estimates of > 100% willingness for some subgroups.  

The total sample included 10,097 MSM.  Awareness, willingness to use and actual use increased significantly over time, with the significant increases in awareness over time and in use in the most recent time period, November 2014-March 2015, compared to May 2012-April 2014 (See Table). The percentage of MSM willing to use PrEP increased from the earliest time point but plateaued after April 2014. Awareness of , willingness to use, and use of PrEP were higher among higher risk MSM, including those recruited from a geospatial sexual networking application, those reporting a bacterial STI, and those with ≥ 10 partners in the last 12 months (See Table).

Awareness and use of PrEP are increasing among internet-using MSM in the US. Though it is encouraging that more higher risk MSM are aware of, willing to use, and have used PrEP, there remains a large gap between the number of MSM who report being willing to use PrEP and those who have actually done so.