# Optimizing an mHealth intervention to improve uptake and adherence of the HIV pre-exposure prophylaxis (PrEP) in vulnerable adolescents and emerging adults

> **NIH NIH R21** · UNIV OF MASSACHUSETTS MED SCH WORCESTER · 2022 · $175,576

## Abstract

Transgender women (TGW), particularly young TGW (ages 18-29), are among the fastest growing HIV+
populations worldwide with HIV prevalence rates of 15-28%. Thailand has the highest adult HIV
seroprevalence in Asia, with high prevalence rates of HIV infection among TGW (18%). Despite their risk, few
interventions have targeted young TGW. Effective developmentally- and culturally-tailored interventions are
needed to prevent HIV transmission in this high-risk population. Widespread technology offers opportunities
for innovative mobile (mHealth) interventions. Pre-exposure prophylaxis (PrEP) is an efficacious HIV
prevention strategy recommended by the CDC and WHO for at-risk individuals, including HIV-negative TGW.
PrEP is highly effective when taken as prescribed, but PrEP uptake and adherence have been low, with high
discontinuation rates among TGW. To address these challenges, we propose to develop and pilot a multi-
component, technology-based intervention to promote PrEP usage. We will adapt an existing two-session,
technology-delivered, Motivational Interviewing intervention to focus on PrEP use in young Thai TGW,
resulting in the Motivational Enhancement System for PrEP Uptake and Adherence (MES-PrEP). We will also
refine and enhance “YaCool,” a mobile app with integrated text messaging developed and used clinically by our
Thai team, to develop “enhanced YaCool” for TGW self-management of gender/sexual health (including PrEP).
Our primary aim is to develop and assess preliminary efficacy of the resulting mHealth intervention. We will
utilize a Multiphase Optimization Strategy (MOST) to identify the most effective intervention component or
combination of components to address PrEP usage in this population. The proposed study includes 2 phases
corresponding to the R21 and R33 study periods. Phase IA (R21) includes qualitative interviews with key
stakeholders to explore barriers and facilitators of PrEP usage through thematic analysis to inform intervention
adaptation. Phase IB (R21) consists of adapting and beta testing of MES-PrEP and enhanced YaCool for
functionality and feasibility using a community advisory board of HIV-negative Thai TGW. In Phase II (R33),
we will conduct a MOST design-based trial to evaluate the feasibility, acceptability, and preliminary efficacy of
MES-PrEP and YaCool. Eighty HIV-negative young TGW who are on PrEP and 80 young TGW who are not
starting PrEP will be randomized to four experimental conditions: 1) Standard PrEP Counseling (SPC, control),
2) MES-PrEP + SPC, 3) enhanced YaCool + SPC, and 4) MES-PrEP + enhanced YaCool + SPC. Feasibility and
acceptability of the intervention will be assessed through usage patterns and the System Usability Scale.
Preliminary impact will be assessed by evaluating the proportion of PrEP initiation and level of adherence to
PrEP. TGW will complete assessments at baseline and 1, 3, 6, 9, and 12 months post-intervention. Biomarkers
of adherence to PrEP and HIV/STI will be collected. U...

## Key facts

- **NIH application ID:** 10469457
- **Project number:** 5R21HD107988-02
- **Recipient organization:** UNIV OF MASSACHUSETTS MED SCH WORCESTER
- **Principal Investigator:** Karen MacDonell
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $175,576
- **Award type:** 5
- **Project period:** 2021-08-13 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10469457

## Citation

> US National Institutes of Health, RePORTER application 10469457, Optimizing an mHealth intervention to improve uptake and adherence of the HIV pre-exposure prophylaxis (PrEP) in vulnerable adolescents and emerging adults (5R21HD107988-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10469457. Licensed CC0.

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