# Optimizing a Just-in-Time Adaptive Intervention to Increase Uptake of Chemsex Harm Reduction Services in MSM: A Micro-randomized Trial

> **NIH NIH R01** · UNIVERSITY OF CONNECTICUT STORRS · 2024 · $773,845

## Abstract

ABSTRACT
 Chemsex, the use of psychoactive drugs before or during sexual activity, is a growing public health concern
due to its association with increased HIV transmission and other harms, particularly among men who have sex
with men (MSM). Current estimates suggest that 9-26% of Malaysian MSM participate in chemsex, contributing
to recent increases in HIV prevalence. In the absence of evidence-based interventions for chemsex, harm
reduction strategies remain the most impactful approach to mitigating chemsex-associated
harms. However, getting harm reduction interventions to MSM who engage in chemsex is a major challenge
due to the spontaneous and dynamic nature of chemsex risk. Just-in-time adaptive interventions (JITAIs)
delivered via smartphones represent a powerful strategy to deliver support by deploying tailored intervention
when needed. Specifically, apps that incorporate JITAI can be more effective than traditional app-based
interventions by addressing the dynamic nature of chemsex risk and capitalizing on users' changing states of
vulnerability (heightened chemsex risk behaviors) and receptivity (willingness to engage in intervention), while
also minimizing user burden, disruption, and habituation. Although JITAIs are increasingly being used in
domains such as addiction, mental health disorders, physical inactivity, and obesity, research on JITAIs to
address chemsex harm reduction is non-existent. In response, we developed JomCare, a smartphone app-based
chemsex harm reduction JITAI, that uses a machine learning algorithm to determine risk and deliver tailored
support as needed. JomCare includes several `pull' and `push' intervention components based on the
information-motivation-behavioral skills (IMB) model, and has demonstrated high feasibility and utility
in our recent pilot work. However, little is known to guide which intervention components should be
delivered in specific contexts to achieve maximum benefit, thus indicating the need to optimize JomCare. Framed
by the multiphase optimization strategy (MOST) and building on our formative work, we will optimize
JomCare using a micro-randomized trial (MRT) to evaluate: i) which theory-driven intervention
components are efficacious in reducing chemsex risk behaviors; and ii) which contexts influence the efficacy of
JomCare. Specifically, we will conduct a 90-day MRT of the JomCare JITAI among 482 chemsex-involved
Malaysian MSM. Participants will be randomized twice daily via the app to receive: i) no prompt; ii) a generic
engagement prompt; or iii) one of three IMB model-based engagement prompts. The specific aims of this
application include: i) Evaluate the effects of any intervention (i.e., theory-driven or generic engagement
prompts) versus no intervention on chemsex risk behaviors (proximal outcomes) at subsequent EMAs following
randomization; ii) Compare the effects of theory-driven and generic engagement prompts on proximal outcomes;
and iii) Examine contextual moderators of inte...

## Key facts

- **NIH application ID:** 11006733
- **Project number:** 1R01DA061661-01
- **Recipient organization:** UNIVERSITY OF CONNECTICUT STORRS
- **Principal Investigator:** Roman Shrestha
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $773,845
- **Award type:** 1
- **Project period:** 2024-07-15 → 2029-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11006733

## Citation

> US National Institutes of Health, RePORTER application 11006733, Optimizing a Just-in-Time Adaptive Intervention to Increase Uptake of Chemsex Harm Reduction Services in MSM: A Micro-randomized Trial (1R01DA061661-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11006733. Licensed CC0.

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