Who is using PrEP on-demand? Factors associated with PrEP use modality among Black and Hispanic/Latino emerging adults.

Pre-exposure prophylaxis (PrEP) is a highly efficacious HIV prevention medication, yet Black and Hispanic/Latino sexual minority men's and gender diverse individuals' (SMMGD) PrEP use is limited due to factors such as PrEP barriers and anticipated PrEP stigma. Although most individuals who use PrEP take it as a daily regimen, there is evidence that many SMMGD are interested in using "on-demand" (also known as event-driven or intermittent or 2-1-1) PrEP. We used stepwise multinomial logistic regression to explore factors associated with on-demand, daily, and no PrEP use among 820 Black and Hispanic/Latino SMMGD ages 18-29 in the United States. We found that greater reported PrEP barriers were associated with higher odds of using PrEP on-demand or not using PrEP compared to daily PrEP use. More past 3-month sex partners and greater comfort telling others about PrEP use were associated with lower odds of on-demand compared to daily PrEP use. In addition, compared to daily PrEP use, more past 3-month sex partners, greater comfort telling others about PrEP use, and higher anticipated PrEP stigma were associated with lower odds of no current PrEP use compared to daily PrEP use. Findings may inform clinical practices and interventions to promote PrEP uptake and adherence.