Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

People who are transgender have a gender identity that differs from the male or female sex assigned to them at birth. Some transgender people get gender-affirming therapies to change their bodies to match their gender identity. For example, some people may get surgery; others take hormones such as estrogen or testosterone. Gender-affirming therapies have been shown to improve psychological functioning and quality of life for transgender adults.  

In the United States, transgender adults have higher rates of HIV compared with other adults. HIV weakens the body’s immune system and makes it hard for the body to fight off infections. Proper medical care can control HIV, although there is no cure. People who are at risk for HIV can take medicine to prevent HIV infection.

In this study, the research team wants to learn whether and how gender-affirming therapies affect HIV-related health outcomes for transgender adults.

Who can this research help?

Clinicians who care for transgender adults can use results from this study when considering ways to help prevent or manage HIV.

What is the research team doing?

The research team is recruiting 4,500 transgender adults from two health clinics, one in Boston and the other in New York City.

The research team is tracking health records for transgender patients who do or don’t receive gender-affirming therapies over one year. They are comparing records at the start and end of the year to see

  • Whether patients living with HIV take medicine that controls the amount of HIV in their bodies
  • Whether patients without HIV take medicines to reduce their chances of getting HIV
  • Patients’ risk of getting HIV

At the start of the study and again 6 and 12 months later, patients are filling out surveys about their psychological functioning, health-related quality of life, and experiences with gender-affirming therapies. The questions include whether the patients have had gender-affirming therapies, how satisfied they are with these therapies, if the therapies have met their needs, and if they would like to get more of these therapies in the future. The surveys also ask what made it easy or hard to get gender-affirming therapies.

Transgender people are working as part of the research team to plan and guide the study. The team includes staff from the Center of Excellence for Transgender Health and the National LGBT Health Education Center. A community advisory board and a scientific advisory board are also helping the research team.

Research methods at a glance

Design Elements Description
Design Observational: longitudinal, prospective cohort study
Population 4,500 transgender adults ages 18 and older
  • Gender-affirming therapies, such as hormones and/or surgery delivered in primary care
  • No gender-affirming therapies


  • Among HIV infected patients: viral suppression
  • Among HIV-uninfected patients: uptake of preexposure prophylaxis (PrEP)
  • Among all patients: diagnosis of anogenital gonorrhea and/or chlamydia as a proxy for HIV sexual risk

Secondary: among HIV-uninfected patients: HIV incidence

Timeframe 1-year follow-up for primary outcomes

More to Explore...


Gaining Trust in Transgender Communities through Patient-Centered Approach (right)
Study Principal Investigator Sari Reisner, ScD shares how PCORI’s patient-centered approach allowed his study to gain the trust of the transgender community to improve outcomes and access to health care.

Improving HIV Outcomes in Transgender Populations
Study Principal Investigator Sari Reisner, ScD says a goal of this study is to look at whether the delivery of gender-affirming treatments, such as hormones or surgery, can improve HIV outcomes for transgender people engaged in care.

Project Information

Sari Reisner, ScD
Brigham and Women's Hospital
Transgender Cohort Study of Gender Affirmation and HIV-related Health

Key Dates

November 2017
April 2023

Study Registration Information


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Funding Opportunity Type
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: November 30, 2022