UC San Diego

Abstract: Background: Technology has changed the way men-who-have-sex-with-men (MSM) seek sex; ≥60% of MSM in the United States use the internet to find sex partners, primarily via Grindr™ which is the most used dating app among MSM. Studies to date have mostly evaluated Grindr™ use as a dichotomous variable and found inconsistent results regarding associations with increased HIV risk behavior. Importantly, Grindr™ “on-screen” activity is monitored by phones and can provide an objective measure of app usage. Here we aimed to assess Grindr™ “on-screen” activity in MSM undergoing community-based HIV and sexually transmitted infection (STI) screening in San Diego, and to correlate activity with sexual risk behavior and substance use. Methods: This nested cohort study was conducted between December 2018 and April 2019 and leveraged our “Good to Go” (AI106039) screening program for participant recruitment. During their testing encounter participants not on HIV PrEP were provided with surveys on demographics, substance use and risk behavior during previous 3 months, and Grindr™ usage. Participants with iPhones were instructed on how to assess Grindr™ on-screen activity (i.e., time on-screen during last 7 days) on their phones (Figure 1). Risk behavior was classified using the validated San Diego Early Test (SDET) Score (Figure 2). Results: Overall 378/784 (48%) MSM participants indicated that they had opened Grindr™ during the previous 7 days. Grindr™ users had higher SDET scores than those not using Grindr™ (median SDET 2, IQR 0–5; mean 2.29) while there was no difference in proportion of substance users (alcohol and marijuana excluded, 21% vs. 17%; P = 0.14). Of 231 MSM who indicated recent Grindr™ use (61%) had iPhones; median on-screen activity during the previous 7 days was 144 minutes (range 1–2,640 minutes). Participants with high Grindr™ utilization (>80th percentile of time on screen corresponding to >480 minutes), had significantly higher SDET scores (median 5 vs. 2; mean 4.02 vs. 3.26; P < 0.001) and a tendency toward a higher proportion of substance users (29% vs. 20%) than those with lower Grindr™ utilization. Conclusion: This study introduces Grindr™ on-screen activity as an objective measure that can help identify MSM at high risk for HIV. Disclosures: All Authors: No reported Disclosures.