Pre-implementation Study to Develop Trans-tailored Services for Transgender Persons in Relation to chemsEX (T-REX)

March 31, 2026 updated by: Institute of HIV Research and Innovation Foundation, Thailand
The study is a pre-implementation cross-sectional study exploring chemsex behaviors among transgender persons and gathering perspectives from multiple stakeholders to inform the development of transgender-tailored harm reduction services.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is designed under the EPIS framework (Exploration and Preparation phases) to better understand chemsex use among transgender populations in Thailand.

The study aims to:

  • Explore reasons and patterns of chemsex use
  • Assess positive and negative impacts (physical, sexual, mental, and socio-legal)
  • Identify key components, barriers, and facilitators for developing transgender-tailored chemsex services

Data will be collected using a mixed-methods approach, including:

  • In-depth interviews (IDIs)
  • Self-administered questionnaires Participants include transgender chemsex users, their family/partners, and stakeholders such as healthcare providers and policymakers.

Study Type

Observational

Enrollment (Estimated)

50

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Rena Janamnuaysook, MBA
  • Phone Number: 662 160 5371
  • Email: rena.j@ihri.org

Study Locations

  • Thailand
    • Bangkok
      • Pathum Wan, Bangkok, Thailand, 10330
        • Recruiting
        • Tangerine Clinic, Institute of HIV Research and Innovation
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

G1: Transgender chemsex users

  • Transgender women or transgender men
  • Current or former chemsex users

G2: Family / partners

  • Family members, friends, or partners of transgender persons
  • Never engaged in chemsex
  • Able to communicate in Thai

G3: Stakeholders

  • Healthcare providers, policymakers, law enforcement, counselors, community leaders
  • Involved in chemsex-related care/policy
  • Able to communicate in Thai

Description

Inclusion Criteria:

  • Age ≥18 years
  • Able to communicate in Thai
  • Provide informed consent

Exclusion Criteria:

• Unable to participate in in-depth interview (IDI) (online or onsite)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Transgender Chemsex Users
Transgender women and transgender men who are current or former chemsex users. Participants will take part in semi-structured in-depth interviews (IDIs) exploring chemsex behaviors, patterns of use, perceived impacts, and needs for transgender-tailored harm reduction services.
Behavioral: Understanding of chemsex patterns, impacts, and service needs among transgender persons
: During study period (single visit within ~12 months study duration)
Family Members, Friends, or Partners
Family members, friends, or partners of transgender persons who have not engaged in chemsex. Participants will provide perspectives on the social, behavioral, and relational impacts of chemsex and support needs.
Behavioral: Understanding of chemsex patterns, impacts, and service needs among transgender persons
: During study period (single visit within ~12 months study duration)
Stakeholders
Stakeholders including healthcare providers, policy makers, law enforcement officers, counselors, public health professionals, and community leaders involved in care, policy, or regulation related to chemsex. Participants will be interviewed to identify system-level facilitators and barriers to implementation of services.
Behavioral: Understanding of chemsex patterns, impacts, and service needs among transgender persons
: During study period (single visit within ~12 months study duration)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Key themes on chemsex behaviors and service needs
Time Frame: At interview (single time point)

Qualitative themes identified from semi-structured in-depth interviews, including:

  • Reasons for engaging in chemsex
  • Patterns of substance use
  • Perceived positive and negative impacts
  • Harm reduction practices
  • Needs for transgender-tailored services Themes will be identified using thematic analysis.
At interview (single time point)
Barriers and facilitators to implementation of transgender-tailored chemsex services
Time Frame: At interview (single time point)
Barriers and facilitators to implementation identified using the Consolidated Framework for Implementation Research (CFIR) domains based on stakeholder and participant interviews.
At interview (single time point)
Chemsex-related behavioral and demographic characteristics
Time Frame: At interview (single time point)
Descriptive characteristics of participants, including demographic data, substance use patterns, and behavioral risk factors collected via questionnaire.
At interview (single time point)
HIV-related stigma score
Time Frame: Baseline, Month 3, Month 6

HIV-related stigma will be assessed using the HIV Stigma Scale (HSS). The HSS is a validated instrument measuring multiple domains of stigma, including personalized stigma, disclosure concerns, negative self-image, and concerns with public attitudes.

The total score ranges from 40 to 160, with higher scores indicating greater levels of HIV-related stigma (worse outcome)

Score (range: 40-160)
Baseline, Month 3, Month 6
Transgender-related stigma score
Time Frame: Baseline, Month 3, Month 6

Transgender-related stigma will be measured using the Transgender Identity Survey (TIS) (or instrument used in the protocol). This scale assesses experiences of stigma, discrimination, and internalized transphobia.

Unit of Measure:

Score (range: 20-100)
Baseline, Month 3, Month 6
PrEP adherence (self-reported adherence score)
Time Frame: Baseline, Month 3, Month 6

Self-reported adherence will be measured using a standardized adherence questionnaire assessing the number of doses taken over the past 30 days.

Scores range from 0 to 100%, with higher percentages indicating better adherence (better outcome).

In addition, adherence will be objectively assessed using tenofovir diphosphate (TFV-DP) concentrations in dried blood spots.

Unit of Measure:

Percentage (%) Drug concentration (fmol/punch)
Baseline, Month 3, Month 6
Intervention acceptability score
Time Frame: Month 3

Description:

Acceptability will be assessed using the System Usability Scale (SUS). The SUS is a 10-item questionnaire with scores ranging from 0 to 100, with higher scores indicating better usability and acceptability (better outcome).

Score (range: 0-100)
Month 3

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Institute of HIV Research and Innovation Foundation, Thailand

Collaborators

amfAR, The Foundation for AIDS Research

Investigators

  • Principal Investigator: Nittaya Phanuphak, MD,PhD., Institute of HIV Research and Innovation (IHRI)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 1, 2024

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

May 1, 2027

Study Registration Dates

First Submitted

March 22, 2026

First Submitted That Met QC Criteria

March 29, 2026

First Posted (Actual)

April 1, 2026

Study Record Updates

Last Update Posted (Actual)

April 6, 2026

Last Update Submitted That Met QC Criteria

March 31, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IHRI028

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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