Addressing HIV PrEP care persistence: individual PrEP use trajectories and the impact of a home-based PrEP program Restricted; Files Only
Chen, Yi-No (Fall 2023)
Abstract
Suboptimal persistence in HIV pre-exposure prophylaxis (PrEP) among men having sex with men (MSM) limits its effectiveness. Knowledge gap exists in understanding the long-term patterns of PrEP use. In addition, telemedicine has been proposed as a potential strategy to alleviate PrEP cessation by reducing clinic-based barriers. PrEP@Home is a home-based telemedicine PrEP system designed to minimize patient burden. Since 2019, a randomized controlled trial was launched in U.S. cities to evaluate the efficacy of PrEP@Home on the outcome of PrEP persistence, compared to the standard PrEP care. There is a need to assess whether the relative health benefits generated by PrEP@Home would be an effective investment of limited health resources. The overarching goal of this dissertation was to improve understanding of current PrEP use and potential utilities of scaling up home-based PrEP interventions.
In Aim 1, we used a parametric clustering algorithm (i.e., group-based trajectory model) to group PrEP persistence trajectories over two years among samples of male PrEP users from a national pharmacy chain in the US. We identified four distinct subgroups of PrEP persistence trajectories. Based on their trajectory characteristics, they are labeled as “persistent PrEP use”, “rapidly declining PrEP persistence”, “PrEP initiators” (after initial decline of PrEP use), and “mid-term cessation of PrEP use”. The clinically actionable typology of PrEP persistence patterns informs future PrEP persistence interventions that target heterogeneous timings of PrEP cessations. Older age, having commercial insurance as the primary payer of PrEP, and use of specialty pharmacy were associated with PrEP persistence against various patterns of non-persistence.
In Aim 2, we built an individual-based simulation model parameterized with the interim PrEP@Home’s trial data to assess the cost effectiveness of PrEP@Home program among participants from the trial. The provision of PrEP@Home was associated with increased PrEP persistence in the early months of the trial, but the positive intervention decayed over time. Simulation results suggest that PrEP@Home program was likely an economically dominant intervention with mild superiority on the clinical scale. The probability of PrEP@Home care being cost-effective was estimated to be above 75% regardless of the common cost effectiveness thresholds for high-income countries ($50,000/QALY, $100,000/QALY) we used.
In Aim 3, we used network-based HIV dynamics model to assess the population-level impact of PrEP@Home program on HIV incidence among MSM in Atlanta, GA, when scaled up. Based on the simulations per PrEP@Home’s efficacy estimated from the interim trial data, scaling PrEP@Home only led to marginal reduction in cumulative HIV incidence over a 10-year period (up to 3% reduction at 100% PrEP@Home coverage). Even at maximum PrEP@Home coverage, we found that a minimum PrEP@Home’s efficacy of around 60% were required to reach at least 10% HIV incidence averted over 10 years.
This dissertation not only has contributed to the understanding of heterogenous PrEP persistence patterns (which may be critical for effective PrEP care and retention management in the field), but also shed light on the utility of home-based PrEP program from the cost-saving perspective. It further underscores the need for initiating and expanding other interventions along the PrEP care cascade to maximize the benefit of home-based intervention and achieve substantial reduction in cumulative HIV incidence among MSM in Atlanta.
Table of Contents
Chapter 1 : Background summary & project overview.
Chapter 2 : Describe a typology of PrEP persistence trajectories among male PrEP users in the US through cluster analysis.
Chapter 3 : Evaluate the cost effectiveness of PrEP@Home care in preventing HIV among the participants in the PrEP@Home trial.
Chapter 4 : Understand the population-level impact of PrEP@Home program on HIV incidence among MSM in Atlanta, GA, when scaled-up.
Chapter 5 : Summary of findings & future research.
Chapter 6: References.
About this Dissertation
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File download under embargo until 10 January 2030 | 2023-11-08 16:04:21 -0500 | File download under embargo until 10 January 2030 |
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