CROI 2018 Abstract eBook

Abstract eBook

Poster Abstracts

1019 MONITORING PrEP USE AMONG WASHINGTON STATE MSM: RESULTS OF AN INTERNET SURVEY Darcy W. Rao 1 , Jason Carr 2 , Kelly Naismith 2 , Julia Hood 3 , James P. Hughes 1 , Matthew R. Golden 1 1 University of Washington, Seattle, WA, USA, 2 Washington State Department of Health, Olympia, WA, USA, 3 Public Health–Seattle & King County, Seattle, WA, USA Background: Pre-exposure prophylaxis (PrEP) is a key component of the National HIV/AIDS Strategy. Many state and local health departments now promote and support the use of PrEP, yet monitoring PrEP use at the population level remains challenging. We report results of a statewide Internet survey of men who have sex with men (MSM) designed to measure PrEP use and related behaviors. Methods: We used banner and broadcast advertisements on social media, sexual networking, and LGBTQ-interest websites and apps to recruit MSM to complete an online survey. For this analysis, eligible participants were cisgender men ages 16+ who lived in Washington State, reported oral or anal sex with a man in the past 12 months, and had never tested positive for HIV. Men who had used PrEP provided their dates of first and, if applicable, last use. Past users were asked to indicate their reasons for discontinuing, and men who had never used PrEP indicated their reasons for not initiating. We conducted bivariate and multivariable logistic regression to identify factors associated with PrEP use, and we estimated time to PrEP discontinuation by fitting a Kaplan Meier curve to reported data on time on PrEP. Results: From January 1 to February 28, 2017, a total of 1,080 men responded to the survey and were eligible for this analysis. The median age of participants was 30, 68% identified as non-Hispanic white, and 49% had a 4-year college degree or higher education. Based on WA State guidelines, 33% of participants are recommended to initiate PrEP, and 30%met indications for discussing PrEP with a provider. Overall, 79% of respondents had heard of PrEP, 19% reported current use, and 4% reported past use. Current PrEP use was independently associated with age, higher education, and PrEP candidacy. In Kaplan-Meier analysis, an estimated 19% of men discontinue PrEP within 12 months of initiation (95% CI 14%, 26%). The primary reason for discontinuation was no longer feeling at high risk for HIV (52%). Among men recommended for PrEP, 31% reported current use, and 56% of those who had never used PrEP were interested in starting it. The primary reason for not starting PrEP among MSM for whom state guidelines recommend use was low perceived risk (29%). The survey cost $19 per complete response. Conclusion: Internet-based surveys of MSM are a feasible, low-cost means of monitoring PrEP use. Our findings suggest that PrEP use in WA State is relatively widespread, although the majority of MSM for whom PrEP is recommended are not taking it.

providers who meet YTW’s health needs (β = 2.9, 95%CI = 1.3 – 4.4) were associated with an increase in PrEP acceptability scores, whereas younger age (aged 21-25 vs 26-29 years) (β = –2.0, 95%CI = -3.6 – -0.4) and reporting transactional sex in the last 4 months (β = –1.5, 95% CI = -3.0 – -0.1) were associated with lower PrEP acceptability scores (all p’s<0.05). The majority (66.1%) of YTW in this sample were interested in PrEP use. The most commonly reported reasons for being uninterested in PrEP included 1) concerns related to medication side effects (20.5%) and 2) mistrust with medical providers (16.7%). Conclusion: Overall, PrEP acceptability was high among this community- recruited sample of sexually active YTW. Interventions that seek to build trust between providers and YTW, as well as provide culturally responsive sources of educational materials on PrEP related side effects may bolster PrEP acceptability, particularly among youth or those with recent sex work. PrEP programs that seek to meet YTW’s other health needs (e.g., hormone therapy) in addition to PrEP services may also increase PrEP acceptability. 1018 AUTOMATED IDENTIFICATION OF POTENTIAL PrEP CANDIDATES USING ELECTRONIC HEALTH DATA Douglas Krakower 1 , Susan Gruber 2 , John T. Menchaca 2 , Sharon Ulery 3 , Ira B. Wilson 4 , Kenneth H. Mayer 3 , Michael Klompas 2 1 Beth Israel Deaconess Medical Center, Boston, MA, USA, 2 Harvard University, Boston, MA, USA, 3 Fenway Health, Boston, MA, USA, 4 Brown University, Providence, RI, USA Background: To maximize the population-level impact of pre-exposure prophylaxis (PrEP), healthcare organizations need tools to identify persons at risk for HIV infection. We hypothesized that electronic health record (EHR) data could be used to identify patients (pts) at increased risk for acquiring HIV who might be candidates for PrEP. Methods: We developed and evaluated automated algorithms to predict incident HIV infection using EHR data from a community health center in Boston specializing in health care for sexual and gender minorities. EHR data were extracted for 168 variables potentially associated with incident HIV for all pts with ≥1 clinical encounter during 2011-2016. EHR variables included patient demographics (e.g. age, gender), laboratory tests and results (e.g. tests for HIV and sexually transmitted infections), diagnosis codes (e.g. HIV counseling), coinfections (e.g. hepatitis B or C), suggestive routine care (e.g. anal cytology) and prescriptions (e.g. buprenorphine). Candidate HIV prediction algorithms were developed using machine learning methods (LASSO, ridge regression, random forest) and generalized linear models and were used to estimate risk for incident HIV for all pts. Algorithms were trained using 2011-2015 data and validated using 2016 data; pts using PrEP were excluded from analyses. We assessed algorithm performance using area under the receiver operator curves (AUC), sensitivity, specificity, and positive predictive value (PPV). Results: Of 33,404 pts in care during 2011-2016, 64%were male (of whom 46% identified as gay/bisexual) and 8%were transgender/gender non-conforming, and 68%were white, 8%were Black, and 6%were Latino; HIV prevalence was 9% and 5% of pts used PrEP. In total, 423 pts (1.3%) had incident HIV, including 71 of 18,275 pts in care during 2016. AUCs for candidate prediction algorithms ranged from 0.43 to 0.83; LASSO had the highest AUC. Using a cut-off of the top 20% of patient risk scores, LASSO had a sensitivity of 73%, specificity of 81% and PPV of 1.5% for predicting incident HIV in 2016. We varied this cut-off to explore trade-offs in sensitivity, PPV, and population size identified as screen-positive. (Table) Conclusion: Automated algorithms that integrate EHR data have favorable properties as population-level screening tools to identify patients who merit clinical evaluations for PrEP. Despite low PPVs, these algorithms offer an efficient means of reducing missed opportunities to provide PrEP to those patients most likely to acquire HIV.

Poster Abstracts

CROI 2018 390