Affiliation:
1. Division of Infectious Diseases and Global Public Health, University of California San Diego , La Jolla, California , USA
2. Specialists in Global Health , Encinitas, California , USA
3. Department of Family Medicine and Public Health, University of California San Diego , La Jolla, California , USA
4. Department of Psychiatry, University of California San Diego , La Jolla, California , USA
5. Department of Medicine, Stanford University , Stanford, California , USA
Abstract
Abstract
Background
Timely, accurate adherence data may support oral pre-exposure prophylaxis (PrEP) success and inform prophylaxis choice. We evaluated a Food and Drug Administration (FDA)-approved digital health feedback system (DHFS) with ingestible-sensor-enabled (IS) tenofovir-disoproxil-fumarate plus emtricitabine (Truvada®) in persons starting oral PrEP.
Methods
Human immunodeficiency virus (HIV)-negative adults were prescribed IS-Truvada® with DHFS for 12 weeks to observe medication taking behavior. Baseline demographics, urine toxicology, and self-report questionnaires were obtained. Positive detection accuracy and adverse events were computed as percentages, with Kaplan Meier Estimate for persistence-of-use. In participants persisting ≥28 days, adherence patterns (taking and timing) were analyzed, and mixed-effects logistic regression modeled characteristics associated with treatment adherence.
Results
Seventy-one participants were enrolled, mean age 37.6 years (range 18–69), 90.1% male, 77.5% White, 33.8% Hispanic, 95.8% housed, and 74.6% employed. Sixty-three participants (88.7%) persisted ≥28 days, generating 4987 observation days, average 79.2 (29–105). Total confirmed doses were 86.2% (95% confidence interval [CI] 82.5, 89.4), decreasing over time, odds ratio (OR) 0.899 (95% CI .876, .923) per week, P < .001; 79.4% (95% CI 66.7%, 87.3%) of participants had ≥80% adherence. Pattern analysis showed days without confirmed doses clustered (P = .003); regular dose timing was higher among participants with ≥80% confirmed doses (0.828, 95% CI .796 to .859) than among those with <80% (0.542, 95% CI95 .405 to .679) P < .001. In multi-predictor models, better adherence was associated with older age, OR 1.060 (95% CI 1.033, 1.091) per year, P < .001; negative vs positive methamphetamine screen, OR 5.051 (95% CI 2.252, 11.494), P < .001.
Conclusions
DHFS with IS-Truvada® distinguished adherent persons from those potentially at risk of prophylactic failure. Ongoing methamphetamine substance use may impact oral PrEP success.
Funder
National Institutes of Health
National Institute of Mental Health
Publisher
Oxford University Press (OUP)
Subject
Infectious Diseases,Microbiology (medical)