The Leaky Preexposure Prophylaxis Cascade-Barriers and Facilitators to Preexposure Prophylaxis Uptake and Adherence Among Youth Experiencing Homelessness in the US South: A Mixed Methods Study.

Adherence to preexposure prophylaxis (PrEP) is lower among high-risk populations, including youth experiencing homelessness (YEH). This study determined the feasibility of urine PrEP adherence biomarker testing and examined the barriers and facilitators to PrEP uptake and adherence among YEH. YEH were recruited from a randomized control trial conducted in a large urban setting in southern United States. Interviews ( N = 40) were conducted to identify barriers and facilitators to PrEP uptake and adherence. PrEP urine-based adherence testing feasibility was conducted among those who started on PrEP. Twenty-two participants obtained a prescription and 15 youth completed at least one adherence test. Facilitators and barriers were categorized as individual, interpersonal and community, and structural among PrEP starters and nonstarters. PrEP uptake and adherence were low for eligible YEH. Enriching the understanding of the challenges and facilitators experienced with accessing PrEP for YEH can improve engagement in HIV prevention among YEH.