A US-Based National Virtual Cohort of People Living With HIV at Risk for Viral Nonsuppression: Protocol for the EPI-LoVE Prospective Cohort Study.

Background: Despite advances in HIV treatment, many people living with HIV fail to achieve or maintain viral suppression. Individuals who experience interruptions in HIV care, adherence challenges, and viral nonsuppression are often underrepresented in clinic-based cohort studies. Virtual cohort methodologies offer opportunities to recruit, engage, and retain these populations while integrating longitudinal behavioral, biomarker, and digital engagement data needed to characterize dynamic changes in HIV care engagement and viral suppression. Objective: The Exploring, Predicting, and Intervening on Long-Term Viral Suppression Electronically (EPI-LoVE) study was developed to establish a national virtual cohort of people living with HIV with current viral nonsuppression or at an elevated risk of future viral nonsuppression. We describe the study design, recruitment, data collection methods, retention strategies, and baseline cohort characteristics. Methods: Participants were recruited through digital advertising, a national HIV care provider network, and referrals from previous research studies. Eligible participants were adults living with HIV who were currently virally unsuppressed or considered at elevated risk of future viral nonsuppression based on a history of detectable HIV viral load, recent missed HIV care appointments, or a qualifying mental health diagnosis. Following online screening, participant eligibility was confirmed through telephone verification and supporting documentation. Participants completed online surveys every 3 months and HIV viral load assessments every 6 months over 24 months. Data were collected through a study-specific mobile health platform integrating longitudinal behavioral surveys, remote biomarker collection, app engagement metrics, and frequent "Speak Up" microassessments of time-varying behavioral and psychosocial factors associated with HIV care engagement and viral suppression. Results: The study was funded in May 2023. Participant recruitment occurred between February 2024 and June 2025, and longitudinal data collection is ongoing, with study findings anticipated in spring 2028. A total of 4789 individuals expressed interest in the study, 2739 completed screening, and 2262 met eligibility criteria. A total of 1109 consented, and 1051 enrolled. Among the 2262 eligible participants, 63.4% (n=1435) qualified based on a detectable viral load during the previous 12 months, whereas the remainder qualified based on recent missed HIV care appointments or a qualifying mental health diagnosis. Among the 1051 participants, the cohort was predominantly Black or African American (n=677, 64.4%), with a median age of 36 (IQR 31-43) years; 70.8% (n=744) reported recent substance use, and 63.7% (n=669) screened positive for moderate-to-severe depressive symptoms. Baseline HIV viral load data were obtained from 863 (82.1%) participants. Conclusions: EPI-LoVE demonstrates the feasibility of recruiting, verifying, and engaging a geographically diverse national virtual cohort of people living with HIV at elevated risk of viral nonsuppression. By integrating longitudinal behavioral assessments, biomarker collection, and digital engagement data within a single platform, EPI-LoVE provides a scalable framework for studying the dynamic determinants of HIV care engagement and informing future personalized digital interventions.