Abstract Body

A 2015 CDC analysis estimated that 24.7% of sexually active men who have sex with men (MSM) had indications for HIV preexposure prophylaxis (PrEP) based on 2014 US Public Health Service (USPHS) clinical practice guidelines. The USPHS revised those guidelines in 2017, with indications for MSM now targeting MSM based on four base indications: age (18+), HIV status (HIV-negative), recent sexual activity (within 6 months), sexual network configurations (not in a monogamous relationship with a HIV-negative partner); and recent behavioral risk (condomless anal intercourse (CAI) or bacterial STD diagnosis (BSTID) in last 6 months). Updated estimates of the fraction of MSM indicated for PrEP overall and stratified by demographic factors and geography are needed to optimally scale-up PrEP for MSM in the US.

We conducted a national web-based study of 2176 MSM (aged 15–65 who had ever had sex with another man) between July 2017 – February 2018. We estimated the proportion of MSM meeting USPHS-recommended indications for PrEP using the CDC analysis denominator: adult, HIV-negative MSM sexually active in the prior year.

Of 1632 MSM (75%) comprising the CDC denominator, 46.1% (95% CI: 43.7, 48.6) met USPHS indications for PrEP, with percentages consistent across US census regions. Younger MSM (ages 15–24) were least likely to meet PrEP indications: 34.9%. PrEP eligibility varied by race/ethnicity (Black: 51.2%, White 46.3%, Hispanic: 47.1%, Other: 40.4%). Among individuals meeting USPHS PrEP indications, 80.5% were indicated due to recent CAI, 1.9% were indicated due to a recent BSTID, and 17.7% met both indications (CAI and BSTID).

Estimated percentages of MSM meeting indications for PrEP exceeded the previous CDC estimate across race/ethnicity, age, and census regions, with nearly one-half of adult, sexually active, HIV-negative MSM exhibiting indications for PrEP. These differences may reflect a combination of the 2017 changes to USPHS guidelines, increasing risky sexual behavior among US MSM, and rising incidence (and therefore diagnoses) of STIs across the US. This study suggests, given current guidelines for PrEP indications, that a lower fraction of eligible MSM may be receiving PrEP than previously estimated. Additional age- and race/ethnicity-based considerations for PrEP indications may be needed to address rising the higher prevalence of recent STI diagnoses observed among younger and minority MSM in this study and rising HIV case counts in these populations.