Peer-based interventions to support transgender and gender diverse people’s health and healthcare access: A scoping review

Abstract

Background: Pervasive health and healthcare disparities experienced by transgender (trans) and gender diverse (TGD) people require innovative solutions. Peer-based interventions may address disparities, and are an approach endorsed by TGD communities. However, the scope of the literature examining peer-based interventions to address health and healthcare access inclusive of TGD people is uncharted.

Aim: This scoping review aimed to understand the extent of the literature about peer-based interventions conducted with and/or inclusive of TGD populations; specifically, study participants (e.g. sociodemographics), study designs/outcomes, intervention components (e.g. facilitator characteristics), and intervention effectiveness.

Methods: Underpinned by Arksey and O’Malley’s framework: (1) identifying the research question; (2) identifying studies; (3) study selection; (4) charting data; and (5) collating, summarizing, and reporting results, eligible studies were identified, charted, and thematically analyzed. Databases (e.g. ProQuest) and snowball searching were utilized to identify peer-reviewed literature published within 15 years of February 2023. Extracted data included overarching study characteristics (e.g. author[s]), methodological characteristics (e.g. type of research), intervention characteristics (e.g. delivery modality), and study findings.

Results: Thirty-six eligible studies documented in 38 peer-reviewed articles detailing 40 unique peer-based interventions were identified. Forty-four percent (n = 16/36) of studies took place in United States (U.S.) urban centers. Over half (n = 23/40, 58%) focused exclusively on TGD people, nearly three-quarters of which (n = 17/23, 74%) focused exclusively on trans women/transfeminine people. Ninety-two percent (n = 33/36) included quantitative methods, of which 30% (n = 10/33) were randomized controlled trials. HIV was a primary focus (n = 30/36, 83.3%). Few interventions discussed promotion of gender affirmation for TGD participants. Most studies showed positive impacts of peer-based intervention.

Discussion: Although promising in their effectiveness, limited peer-based interventions have been developed and/or evaluated that are inclusive of gender-diverse TGD people (e.g. trans men and nonbinary people). Studies are urgently need that expand this literature beyond HIV to address holistic needs and healthcare barriers among TGD communities.

Introduction

It is estimated that approximately two percent of the global population, including 1 to 1.4 million people living in the United States (U.S.), identify as transgender (trans) or gender diverse (TGD) (Meerwijk & Sevelius, 2017; World Population Review, n.d.) comprising a group of people whose gender identity and/or gender expression differ from societal expectations associated with their sex labeled at birth (Klein et al., 2018). Much research published to-date draws attention to the pervasive health disparities experienced by TGD persons across mental, physical, and sexual health domains (Becasen et al., 2019; Hanna et al., 2019; Reisner et al., 2016; Rich et al., 2020). At the same time, TGD people also experience multiple barriers to accessing healthcare. These barriers can be situated at an individual level, such as a lack of knowledge about where to access affirming care; at an interpersonal level, such as a lack of social support; and at a structural level, such as housing instability or lacking health insurance, particularly comprehensive support that addresses all needs (Lacombe-Duncan et al., 2020a).

Moreover, it is well-known that widespread individual (e.g. internalized anti-trans stigma and low self-worth), interpersonal (e.g. provider mistreatment such as misgendering), and structural anti-trans stigma (e.g. insurance policies that limit TGD peoples’ access to medical gender affirmation) limit TGD peoples’ access to safety, wellbeing, health and healthcare (White Hughto et al., 2015). Indeed, horrifying anti-trans policies that restrict or deny access to medical gender affirmation (e.g. hormone therapy), particularly for young TGD people, have been passed expeditiously across the U.S. (Human Rights Campaign, n.d.), while these conversations are increasing across Europe (Klotz, 2023), and some countries in Africa seek to outlaw the very existence of TGD people (Reuters, n.d.). This multi-level stigma and discrimination contributes to avoidance of needed healthcare among TGD people (Cruz, 2014). Notably, a rapid review identified that 23% (range: 10–40%) of TGD people across eight studies had delayed needed healthcare (Kcomt et al., 2020), and rates of delaying needed healthcare are even higher among TGD people who experience intersecting forms of marginalization, such as TGD people of color (Jaffee et al., 2016). Delaying needed healthcare can have severe negative physical and mental health consequences (Seelman et al., 2017).

Several studies suggest the direct benefits of peer support from other TGD community members toward mental wellbeing of TGD persons, as well as the indirect effect peer support may play in buffering against stigma and discrimination through resilience and empowerment, among other pathways (Harner, 2021; Johnson, 2022; Johnson & Rogers, 2020; Kia et al., 2021, 2023). Although this body of research also recognizes ethical and logistical concerns related to burdening TGD people to care for each other in the absence of structural change (Johnson, 2022; Kia et al., 2023), ultimately this research suggests that peer support may be part of an innovative solution to face the multi-faceted barriers to healthcare experienced by TGD people. Research conducted with TGD people has consistently suggested that peer-based interventions may be effective at increasing access to healthcare and are most desired by TGD communities (Johnson et al., 2020; Reisner et al., 2016). Peer-based interventions are defined as any intervention that relies on peers (i.e. community members, ideally of similar identity to recipients) to either lead the intervention or assist in delivery of the intervention. Peer-based interventions recognize the substantial expertise and the leadership capacity of TGD communities, as well as provide employment opportunities for TGD people, who often face employment discrimination as yet another barrier to health (Bradford et al., 2013; Lacombe-Duncan et al., 2020b).

There are currently some peer-based models being delivered in both hospital (e.g. Trans Buddy Program through Vanderbilt Hospital) and community-based settings (e.g. Fenway Health) (Transgender Health – Fenway Health, 2016; Vanderbilt University Medical Center, n.d.). Programs like these primarily focus on providing emotional support and systems navigation. However, the extent to which peer-based programs that address healthcare access for TGD people have been developed and studied remains under-studied.

Thus, this review sought to describe the scope of the literature about peer-based interventions conducted with/inclusive of TGD populations. Specifically, we aimed to chart gaps with respect to diverse inclusion of study participants across sociodemographic factors (e.g. race/ethnicity), as well as the intervention activities and outcomes. Scoping reviews are especially useful when studying broader topics like peer-based interventions, and they assist in mapping underlying concepts and common themes in the existing research (Arksey & O’Malley, 2005; Levac et al., 2010; Munn et al., 2018). The aim of this article is to inform development of peer-based interventions in ways that are most responsive to community needs and social justice for TGD people.

Materials and methods

This scoping review utilized the methodological framework laid out by Arksey and O’Malley (2005), later expanded upon by Levac et al. (2010) and applied in team settings (Daudt et al., 2013). The five stages of the framework include (1) identifying the research question; (2) identifying relevant studies; (3) selecting the studies; (4) charting the data; and (5) collating, summarizing, and reporting the results (Arksey & O’Malley, 2005).

Stage 1. Identifying the research question

Balancing the need for both a broad scope and specific direction, this review addressed the questions: What is the scope of the literature with respect to the study of peer-based interventions for TGD populations, specifically regarding sample characteristics (e.g. sociodemographic characteristics, geographic setting)? What outcomes have been studied in empirical literature about peer-based interventions with TGD populations using what study designs? What are the core components of these interventions (e.g. activities utilized, level of structure, facilitator characteristics and training)? What does the existing research say about their effectiveness?

Stage 2. Identifying relevant studies

To identify relevant studies, key words used for article searching were intentionally broad to maximize identification of studies, and included ‘transgender’ AND ‘peer’, ‘peer-based’, ‘peer-led’, OR ‘peer intervention’. Databases accessed were ProQuest, Taylor & Francis, PubMed, Oxford Academic, and Routledge using the University of Michigan Library. The reference lists from relevant studies were also reviewed as part of the search, and reverse look-up was used on Google Scholar to search for those studies that had cited the included studies, both forms of snowball searching whereby a key document is used as a starting point for the search (Greenhalgh & Peacock, 2005). Grey literature on peer-led interventions were also used to search for studies on those interventions. Databases were searched using the intervention name and researcher’s names. The search was last updated February 6^th, 2023, near the date of submission.

Stage 3. Study selection

Articles were independently searched and selected by CW and LH and confirmed by ALD. Consistent with recommendations by Levac et al. (2010), CW and ALD met at the beginning of the scoping process, and CW ALD or LH and ALD met regularly throughout. Selection occurred by reviewing articles based on pre-specified inclusion criteria. Inclusion criteria were studies that: (a) focused on peer-based or peer-led interventions with the goal of improving health outcomes or health-promoting behaviors, inclusive of physical, mental, spiritual, and/or social health and well-being and healthcare access; (b) either focused exclusively or explicitly stated inclusion of TGD persons, which included studies that focused more broadly (e.g. lesbian, gay, bisexual, transgender, and queer [LGBTQ+] people, people who use drugs, etc.), so long as the study explicitly and at bare minimum included a quantitative description of the gender breakdown of participants; (c) published in English; and (d) published within the last 15 years. Studies not meeting these criteria were excluded. The 15-year timeframe was set to account for the changing sociopolitical context including increasing calls for human rights and health equity for trans persons that has, and continues to occur, globally (Divan et al., 2016; Thomas et al., 2017).

Stage 4. Charting the data

Using Arksey and O’Malley (2005) framework, data from each article were extracted and charted into an Excel form with the categories of ‘source (e.g. database)’, ‘year’, ‘authors’, ‘title’, ‘journal’, ‘APA reference’, ‘abstract’, ‘keywords’, ‘type of study (e.g. empirical research, commentary)’, ‘location (e.g. geographic setting)’, ‘research questions/goals/aims’, ‘sample size and participant identity characteristics’, ‘methods’, ‘outcomes’, ‘measures’, ‘findings’, and ‘study strengths and limitations’. We also extracted data pertaining to intervention characteristics (e.g. delivery modality).

Stage 5. Collating, summarizing, and reporting results

We began our analyses by summarizing key facets of the data numerically (e.g. number of studies overall, number of studies set in particular settings, number of studies specific to TGD populations), aligned with our key research questions. We then thematically analyzed the core components of each intervention, exploring aspects such as underlying theory, delivery modality (e.g. group versus individual), times met, topics discussed, level of structure, and facilitator characteristics and training. Finally, we synthesized evidence related to their effectiveness. CW and LH conducted the preliminary analyses, which were then reviewed and confirmed by ALD.

Results

The search yielded 36 studies detailed in 38 peer reviewed published articles that qualified for review, describing 40 unique interventions with peer-led components (Table 1). Table 1 reports research details (research aim(s), location(s), participants, study design and sampling strategies, outcome(s) studied, key effectiveness findings). In-depth details regarding the core components of each intervention (name, underlying theory and/or evidence-based intervention(s), delivery modality, times met, activities conducted, peer facilitator characteristics, facilitator training/intervention fidelity measures) are presented in Table 2. The following results are presented consistent with our research aim of describing the scope of the literature about peer-based interventions conducted with TGD populations: sample characteristics, outcomes studied, core components of interventions, and intervention effectiveness.

Table 1.

Research characteristics of studies detailing/examining peer-based interventions to support transgender and gender diverse people’s health and healthcare access (n = 36 studies, detailed in n = 38 articles).

Author(s) & Date	Research aim(s)	Location(s)	Participants	Study Design and Sampling Strategies	Outcome(s) Studied	Key Effectiveness Findings
Altaf et al. (2022)	Test acceptability and feasibility of HIV self-testing among transgender persons in Pakistan	Larkana, Pakistan	Trans people who were HIV negative or had not tested in the last six months, ages 18+; n = 150	Quasi-experimental Pilot study; recruited from peer community outreach Quantitative pretest questionnaire, qualitative post-test questionnaire	Acceptability and ease of use, preferences for accessing HIV self-testing in the future	92.6% of participants reported oral HIV self-testing was acceptable (n = 139) 96.6% of participants found peer outreach worker model to be acceptable (n = 145)
Barrington et al. (2021)	Test acceptability and outcomes of a multilevel individual counseling, peer navigation, and community mobilization intervention to improve HIV outcomes among trans women sex workers	Santo Domingo, Dominican Republic	Trans women living with HIV, who had exchanged sex for money in the past month, ages 18+; n = 30	Quasi-experimental and qualitative Pilot study; recruited from community outreach, informant, and peer referral Socio-behavioral survey at baseline and 12-month follow-up; and qualitative interviews	Uptake and acceptability of intervention components, intervention retention, adherence to ART	Individual counseling had the highest acceptability (96.2%), followed by community mobilization (84.6%), followed by peer navigation (80.8%) Initial lack of trust and concerns about effectiveness were two main barriers to peer navigation Fewer participants missed HIV appointments (p < 0.39) Significant increase in reports of ever taking ART (p < 0.03), and reduction in missed doses (p < 0.50)
Blackstock et al. (2021); Walters et al. (2021)	Assess a pilot peer outreach and peer navigation PrEP intervention for women	East Harlem, New York City, New York, United States The Bronx, New York City New York, United States	Women (cis and trans), ages 18+, receiving services at the partnered community-based organization, HIV status negative or unknown; n = 56 total (n = 6 trans individuals, 10.7% of sample) (Blackstock et al.) Self-identified women (including trans women and other trans femi-nine identities), ages 18+, receiving services from the partner CBO; n = 32 total (n = 3 trans women, 0.09%) (Walters et al.).	Quasi-experimental and qualitative Pilot study, recruitment from recipients of services from community-based organization (Blackstock et al.) Semi-structured qualitative interviews (Walters et al.)	Linkage to PrEP care, PrEP uptake, facilitators and barriers to the intervention	27 (51.9%) accepted the offer of a PrEP care appointment 3 (5.8%) attended an initial PrEP care appointment 0 received a PrEP prescription 36 (69.2%) were referred to other needed health and social services (Blackstock et al.) Despite reporting a high level of HIV-related worry and access to health care, self-perceived HIV risk was low and only half were previously aware of PrEP Participants expressed overall favorable experiences, and peers’ involvement had a significant and positive impact Barriers to care were: lack of perceived HIV risk, concerns about medication interactions, housing insecurity and travel, co-occurring conditions, and caregiving responsibilities (Walters et al.)
Colson et al. (2020)	Compare effectiveness between enhanced PrEP support and standard of care	Harlem, New York City, New York, United States	African American or Black, assigned male sex at birth, living in NYC, having condomless anal or neovaginal intercourse with a male or a trans woman in the past 6 months or having an ongoing partnership with an HIV-positive male or trans woman, ages 18+; n = 204 total (n = 10 trans women, 4.9% of sample)	Experimental (RCT) Two-arm randomized controlled trial with baseline, 3-, 6-, 9-, and 12-month follow-up interviews; utilizing referrals from other studies and targeted outreach	Adherence to PrEP	No statistically significant difference between arms Overall self-reported PrEP adherence declined at each timepoint with 30% adherent at 12 months Lower levels of education and having depressive symptoms had lower levels of adherence No significant relationship was found between 12-month adherence and peer navigation
Cunningham et al. (2018)	Test effect on viral suppression of peer navigation intervention compared with standard transitional case management	Los Angeles, California, United States	Cis men or trans women living with HIV, recently incarcerated, ages 18+; n = 356 total (n = 53 trans women, 14.9% of sample)	Experimental (RCT)	HIV viral suppression, HIV carea, retention and adherence knowledge, quality of life, utilization of other types of healthcareb, substance use	Intervention prevented declines in viral suppression compared to standard of care Linkage to HIV care greater in peer intervention group at 6 months, no difference at 12 months Improved knowledge in intervention group at 12 months Intervention group greater increase in utilization of other types of health care No intervention effect on reported substance use, declined in both arms
Deering et al. (2011)	Examine determinants of using a peer-led mobile outreach program Evaluate relationship between program exposure and utilizing addiction treatment services	Vancouver, Canada	Cis and trans women, substance use in past month, engaged in sex work, ages 14+; n = 242 total (n of trans women specifically not specified)	Quasi-experimental Prospective cohort study with baseline and bi-annual interview questionnaires, utilizing time-spacing sampling, social mapping, and targeted outreach	Uptake of intervention, substance use treatment utilizationc	Participants at higher STI and violence risk more likely to access program Participants who used program more likely to use substance use treatment
Gamariel et al. (2020)	Learn more about men who have sex with men and trans woman who have been accessing a peer-driven education program, their experiences of accessing MSM- and trans-friendly services and their use of face-to-face and virtual networks, including social media, for engagement with health care	Beira, Mozambique	Trans women and cis MSM, ages 19–47; n = 27 total (n = 9 trans women, 33.3% of sample)	Qualitative interviews, purposive and snowball sampling	Not applicable	Peer-driven models of engagement were appreciated, but limited
Garofalo et al. (2012)g; Garofalo et al. (2018)	Evaluate the acceptability and feasibility of the intervention (2012) and whether the intervention reduces condomless vaginal or anal sex among young transgender women compared to standard of care (2018)	Boston, Massachusetts, United States Chicago, Illinois, United States	n = 39 trans women participated in the intervention and survey (2012) People assigned male sex at birth, identifying on the transfeminine spectrum, ages 12–29, English-speaking, with self-reported sexual risk in the last 4 months; n = 190 (2018)	Qualitative and experimental (RCT) Qualitative interviews (2012) Randomized clinical trial, cohort study with baseline assessment and HIV and STI screening, with 4-, 8-, and 12-month follow up (2018)	Rate of condomless sex acts (2018)	>94% of participants reported that the program helped them understand unhealthy behavior and create positive goals for the future (2012) Participants in the intervention arm showed 39.8% greater reduction in condomless sex acts at 12-month follow-up (2018)
Gillard et al. (2022)	Evaluate the effectiveness of peer support in reducing readmission to inpatient mental health treatment	England, United Kingdom	Individuals in psychiatric inpatient treatment with at least one previous inpatient admission, without diagnosis of an organic mental disorder, eating disorder, learning disability, or drug or alcohol dependency, ages 18+; total n = 530, peer support intervention n = 294; total trans participants, n = 3 (0.57%)	Experimental (RCT) Parallel, two-group, randomized controlled superiority trial	Readmission to psychiatric inpatient care	47% of the peer support group were readmitted to psychiatric inpatient care within 12 months (n = 136) compared to 50% of the care as usual group (n = 146) One-to-one peer support did not have a significant effect on psychiatric readmission Patients of Black ethnicity in the peer support group were significantly less likely to be readmitted than patients of any other ethnicity
Hirshfield et al. (2021)	Compare health outcomes between participants who became Peer Leaders and those who did not	New York City, New York, United States	Trans women (mostly Latina) living with HIV, ages 18+; n = 163	Quasi-experimental Pre- and post-comparison of those who became Peer Leaders and those who did not	HIV viral load, CD4 count, HIV care, utilization of other types of health care, access to legal gender affirmation	Becoming a Peer Leader was associated with increased uptake of HIV care, decreased viral load, and increased CD4 count
Kaplan et al. (2019)	Measure feasibility, acceptability, and impact of a trans-facilitated group support intervention in the Middle East, to address sexual and mental health of transgender women with mixed HIV status	Beirut, Lebanon	Assigned male sex at birth, identifying as feminine, ages 18+, ability to give informed consent in Arabic or English; n = 16	Quasi-experimental Baseline survey, 6 post-intervention face-to-face surveys, and 3- and 6-month post-intervention follow-up Peer recruitment using social networks	Feasibility and acceptability of venue, group dynamics, facilitation, content, and retention	88–98% of participants agreed or strongly agreed with positive statements about the peer facilitator Participants described feeling less alone due to the intervention 15 of 16 participants attended all 6 sessions and were retained at 6-month follow-up Further training of the peer facilitator and/or presence of an HIV/STI prevention specialist was requested
Klotzbaugh and Fawcett (2023)	To describe gender minority peoples’ perceptions of their experience in a peer-led support group and identify priorities for their well-being	Southwestern United States	Gender minority persons, ages 18+, English speaking; n = 24	Qualitative Single 60-minute interview at the place of the participant’s choosing Flyering and snowball sampling	Not applicable	Themes identified in the support group: exploration of gender and transition, self-acceptance, identity, safety, stressors, community engagement, and positive outlook
Kuhns et al. (2021)	To evaluate the feasibility and efficacy of an intervention to address social determinants of engagement in HIV care among transgender women of color	Chicago, Illinois, United States	Trans women of color, ages 18+, HIV positive; n = 120	Quasi-experimental Prospective single arm trial carried out over a 24-month follow-up-period Survey at baseline and every six months thereafter	Linkage to HIV care, engagement in care, retention in care, use of ART and viral suppression	Housing services and on-site, outreach-based, medical services were most frequently accessed by participants Access to drop-in HIV services without an appointment created an accessible entry or re-entry point Participants who received adjunctive (non-HIV-related) services were more likely to engage in HIV care and be retained in care 48% of participants engaged in adjunctive services Engagement and retention in HIV care decreased over time Introducing ongoing peer navigation services enhances duration of engagement in intervention for those wanting more limited services at point of initial program participation
Lapadula et al. (2023)	To test the feasibility and acceptability of oral rapid HIV and HCV testing for trans women sex workers	Milan, Italy and Monza, Italy	Trans women engaging in sex work; offered testing n = 126; surveyed, n = 78	Quantitative descriptive Pilot study	Sexual practices, HIV and STI awareness, PrEP attitude, uptake of HIV and HCV testing	42% of participants offered an HIV oral test accepted the test (n = 53), of those not tested 19.8% already knew they were positive 52% of participants offered an HCV test accepted the test, 45% declined All those who tested HIV-positive (n = 7) were linked to care but did not attend their first appointment Extended outreach efforts including text messaging resulted in 6 of 7 being linked to care 3 months later
Lippman et al. (2022)	To measure acceptability and feasibility of peer navigation toward gender affirmation health goals, among trans women living with HIV	São Paulo, Brazil	Trans women living with HIV, ages 18+; n = 75	Experimental (RCT) Community-based outreach and referral from a Transnational Cohort Study	Acceptability, feasibility of peer navigation, and adherence to HIV care and ART	85% would continue peer navigation if offered 94% would recommend peer navigation to a friend 83.3% found peer navigation somewhat or very helpful Intervention participants were ∼40% more likely to be in care at the end of follow-up Only 30% fully adhered to the program, due to multiple challenges in sustaining participation
Martinez et al. (2019)	Explore need for interventions that respond to the complex, interacting syndemic factors that determine HIV vulnerability among trans people; explore how a peer-led intervention promotes prevention and linkage to services such as primary care	Philadelphia, Pennsylvania, United States	>1500 trans individuals	Quantitative descriptive Program evaluation data	Uptake of the intervention	Peer-led program has reached > 1500 trans individuals since 2003 In 2016, program reached 56 trans individuals (11 living with and 45 at-risk of HIV) through 230 sessions In 2017, program reached 80 trans individuals, 97% identified as Black or Latinx
Mwango et al. (2022)	Test the effectiveness of peer-to-peer delivery of HIV testing, counseling, and prevention services	Zambia	1860 TGD individuals	Quantitative descriptive Retrospective analysis of aggregate program data	Testing, test results, linkage to care, uptake of PrEP	87.2% trans persons reached declined HIV testing (n = 1,436) 97.4% of those who tested positive were linked to treatment (n = 76) 77.5% of HIV negative participants initiated PrEP (n = 268)
Nagot et al. (2022)	Assess whether community-based Hepatitis C Virus (HCV) screening and immediate treatment can efficiently detect and treat people who use drugs with chronic HCV	Montpellier, France	People who currently use drugs, ages 18+, HCV-seropositive; n = 181 (n = 2 trans individuals, 1% of sample)	Quantitative descriptive Demonstration project through a respondent-driven sampling survey	Treatment and cure of chronic HCV	615 people were effectively tested for HCV, Hepatitis B, and HIV; of those 181 were found to be HCV-seropositive 49 people who were HCV-seropositive were found eligible for treatment; 30 of those completed treatment; 27 were cured at 12 wk
Pascom et al. (2016)	Evaluate effectiveness of a peer point-of-care testing intervention to increase HIV testing among sex workers, trans people, and men who have sex with men	Brazil	n = 29,723 (n = 1,612 trans individuals, 5% of sample)	Quantitative descriptive Pilot study	HIV testing	2.7% of people who were tested were positive for HIV; 10.7% of trans individuals tested were positive Peer point-of-care testing in convenient locations facilitated access for those with the highest HIV burden Peer testing prevented exposure to discrimination in a healthcare setting
Pawa et al. (2013)	Assess effectiveness of a peer-led HIV prevention program	Pattaya, Thailand	Trans people who are sexually attracted to cis men who had penetrative sex with more than one sexual partner in the past three months; n = 308	Quasi-experimental evaluation, cross-sectional survey and time-location sampling	Condom use, HIV testing	Participation in outreach component associated with condom/water-based lubricant use with commercial partners Attendance at drop-in center associated with HIV testing
Rajabiun et al. (2022)	Evaluate a peer intervention to improve HIV health outcomes for out of care and newly diagnosed women of color	Chester, Pennsylvania, United States Chicago, Illinois, United States Nashville, Tennessee, United States	Women of color who had not seen a healthcare provider in 6 months or were newly diagnosed in the past 12 months, ages 18+; n = 173 (n = 20 trans women, 11.6% of sample)	Quasi-experimental Type 3 effectiveness-implementation hybrid design	Linkage and retention in HIV case management and medical care	96% of women were linked to medical care 73% were retained in care 81% were virally suppressed post 12 months For every four encounters with a peer, retention in care and viral suppression increased by 10% Transition from peer support to linkage with a non-peer case manager took longer than expected: on average 7 months
Reback et al. (2019)	Test feasibility, acceptability, and effectiveness of a peer-led PrEP program	Los Angeles, California, United States	Urban trans women and cis MSM experiencing syndemic health disparities & CDC PrEP Risk Index of 10+; n = 187 (n = 58 trans women, 31.0% of sample)	Quasi-experimental Pilot study	PrEP utilization and adherence	∼90% of trans women and MSM linked to PrEP ∼80% of trans women still taking PrEP at 90-day follow-up
Reback et al. (2021)	Test the impact of peer health navigation on identifying and addressing barriers to linkage and retention in HIV medical care; Test the impact of combined peer health navigation plus contingency management on linkage and retention in HIV care	Los Angeles, California, United States	Trans women of color, ages 18–65, and (a) HIV-positive and currently not in HIV care, or (b) had not seen an HIV medical provider in the past 6 months, or (c) not prescribed ART medication, or (d) prescribed ART medication but not adherent; n = 139	Quasi-experimental Cohort study with 6-, 12-, and 18-month follow-up, recruited using: (1) community-wide social network recruitment and engagement methodology; (2) venue- and street-based outreach; (3) dissemination of project flyers; and (4) in-reach at other programs	HIV care, HIV viral load, HIV achieved/sustained viral suppression	Intervention attendance associated with linkage to HIV care and HIV viral load reductions
Rebchook et al. (2022)	Test and compare the effectiveness of HIV care engagement interventions with diverse strategies	United States	Assigned male sex at birth, identify as trans or female, living with HIV, fluent in English or Spanish, and age 18+; n = 858	Quantitative descriptive Analysis of participant survey data and medical chart data	Number of HIV care visits, ART prescriptions, HIV care retention, viral load tests and test results	79% of participants had at least one interaction with intervention staff in a 24-month period Most sites had over 90% participation in intervention components Fewer participants were reached through group sessions (26%) compared to individual sessions (80%) Suppression of viral load increased from 22% at baseline to 38% at 6 months; decreased to 35% at 24 months Trends were similar for HIV care visits, prescription of ART, and retention in HIV care
Rhodes et al. (2020)	Develop, implement, and evaluate a Spanish-language peer navigation intervention to increase HIV testing and condom use	North Carolina, United States	Immigrant Spanish-speaking Latinx cis gay, bisexual, and other MSM and trans women, ages 18–55; n = 166 total (n = 18 trans women, 10.8% of sample)	Experimental (RCT) Community-based participatory research with two-group, randomized, intervention-waitlist control group	HIV testing, condom use	Increased HIV testing among intervention group All study participants reported increased condom use
Sevelius et al. (2020)	Evaluate feasibility of a peer-led, group-level intervention for trans women emphasizing empowerment and gender affirmation to reduce HIV risk behaviors and increase social support	San Francisco, California, United States	Trans women, ages 18+, reported condomless sex in the past 3 months; n = 25 participated in the intervention, n = 38 control participants	Experimental (RCT)	Condomless sex, number of sexual partners, social support, and feasibility of the intervention	Of Sheroes participants: 82% attended all 5 sessions; most expressed a desire for more sessions 92% reported they were “Extremely satisfied” with their experience There was a significant reduction in reported number of sex partners with whom they had condomless sex (p = 0.007) and an increase in social support (p = 0.04).
Sevelius et al. (2021)	Evaluate a community-led, trans-specific PrEP intervention linking health education, community mobilization, and clinical integration with hormone therapy	Oakland, California United States Sacramento, California, United States	TGD people, ages 18+ interested in PrEP; n = 185	Quasi-experimental Community-led demonstration project Cohort study	PrEP uptake, retention, and adherence	91% of participants initiated PrEP during the intervention Participants who perceived higher HIV risk were more likely to be adherent Participants who had been exposed to violence were less likely to be retained or adhere to PrEP 43% of participants were retained for the full 12 months
Sevelius et al. (2022)	Test the efficacy of a gender affirming HIV care intervention for trans women impacted by HIV	San Francisco, California United States Los Angeles, California, United States	Assigned male sex at birth but not currently identified as male, age 18+, living with HIV, with reported suboptimal engagement in HIV care; n = 139	Experimental (RCT)	Engagement in HIV care, ART adherence	Participants of the intervention were twice as likely to be highly engaged in HIV care at 6 months Increase in care engagement was delayed (not significant at 3 months) High levels of care engagement were not sustained (not significant at 9 or 12 months)
Sevelius et al. (2023)	Evaluate feasibility and acceptability of a trans-specific re-entry support intervention	San Francisco, California	Transfeminine people currently incarcerated for a minimum of 1 week remaining on their time, age 18+; n = 14	Experimental (RCT)	Goals and service needs identified, outcomes	100% of participants who received the intervention felt that they had benefited from participation Findings highlighted the importance of peer facilitators Housing was the most commonly cited service need among both intervention and control groups All three participants who identified trans-specific medical care as a goal were linked to those services upon re-entry
Soe et al. (2022)	Measure the cost of community outreach-based HIV interventions	Thailand	Men who have sex with men (MSM), Trans people, sex workers, people who ingest drugs, migrants; n = 190,931 (n = 98,561 MSM/TG, 51% of sample)	Quantitative descriptive	Screening and testing, cost per unit	Implementing the intervention through preexisting NGOs addressing HIV for MSM/TG populations reduced costs Interventions were most efficient in large metropolitan areas Implementing HIV and TB interventions together increased efficiency for both
Strömdahl et al. (2019)	Evaluate the effectiveness of peer-led HIV testing by an LGBTQ + led community organization, at gay clubs, cruising areas, and video sex clubs in reaching MSM and transgender people	Stockholm, Sweden Örebro, Sweden	Men who have sex with men (MSM), ages 18+; n = 595 (n = 24 trans individuals, 4% of sample)	Quantitative descriptive Survey	HIV testing	20% of all participants had never tested before 27% of trans participants had never tested before 30% of participants had tested 5+ years ago 20% reported they would not have tested within the healthcare system if venue-based testing was not available 0.8% of participants tested positive The intervention was most successful in reaching foreign born MSM (50% of participants), perhaps due to the availability of materials in 5 languages and low-threshold access
Subramanian et al. (2013)	Examine coverage and scale achieved by a peer navigation HIV prevention program; assess changes in selected program outcomes; identify any links between outcomes and exposure to the program	Tamil Nadu, India	Cis men and individuals who self-identified as Aravani (e.g. trans women), ages 18+, engaged in sex work; n = 1621 (n = 404 trans women round 1 of survey, n = 403 trans women round 2 of survey, 24.9% of sample)	Quasi-experimental Two rounds of cross-sectional bio-behavioral surveys among high-risk MSM and trans women and routine program monitoring data	Uptake of intervention, condom use, prevalence of HIV/STI	For trans women, nonsignificant increase in condom use Syphilis declined significantly Nonsignificant HIV prevalence decrease
Webel (2010)	Test the impact of participation in a peer-based intervention for symptom management	San Francisco, California, United States	Adult cis and trans women living with HIV; n = 89 (n = 14 trans women, 15.7% of sample)	Experimental (RCT)	HIV symptom intensity, ART adherence, viral suppression, quality of life	No significant difference between groups across symptom score and medication adherence Intervention group greater increase in quality of life
Willging et al. (2018)	Assess implementation issues related to the feasibility, acceptability, appropriateness, and preliminary impacts of a novel peer-based intervention	Rural New Mexico, United States	LGBTQ persons meeting criteria for a DSM-IV-TR Axis I mental health disorder, ages 18+; n = 47 (n = 8 trans individuals, 17.0% of sample)	Quantitative descriptive and qualitative Exploratory study, mixed methods evaluation	Mental health symptoms, substance use, social support	Qualitative results showed preliminary evidence for the intervention’s effectiveness to enhance social support and self-advocacy All quantitative findings null, trending in expected direction
Wilson et al. (2021)	To determine the overall effectiveness of peer navigation on HIV primary care engagement, ART prescription, and retention in HIV care for trans women of color	San Francisco Bay Area, California, United States	Trans women of color; n = 103	Quasi-experimental Quantitative survey at baseline, 6-month, and 12-month visits	Primary HIV care visits, ART prescription, and retention in HIV care	At 6-month and 12-month follow-up, 64% and 68% of participants received at least some intervention At 6-month and 12-month follow-ups 59% and 52% of participants received peer-delivered interventions The number of participants who had at least one primary HIV care visit or ART prescription increased from baseline to 12-month follow-up Retention in HIV care also increased from 6-month to 12-month follow-up Receiving any amount of peer intervention was positively associated with all measures
Young et al. (2022)	Evaluate the implementation of a community-based dried blood spot (DBS) screening intervention for HIV/HCV among GBT2Q people	Canada	Individuals involved in the intervention (research staff, site coordinators, and volunteer DBS collectors); n = 16	Qualitative interviews about intervention feasibility and effectiveness	Not applicable	DBS sample collection was low barrier Due to DBS sampling not delivering immediate results, testing could be performed by peers rather than healthcare workers Intervention respondents perceived the intervention as “less clinical and more grassroots, trustworthy, and approachable” due to peer delivery People knowingly living with HIV were less likely to get tested due to misunderstanding about eligibility and HIV-related stigma

^a HIV care: linkage to HIV care, retention in HIV care, antiretroviral therapy (ART) use and/or ART adherence.

^b Utilization of other types of health care: primary care provider, specialist care, psychiatric care, emergency department visits

^c Substance use treatment: Methadone maintenance therapy; addiction counseling; inpatient detoxification; and residential drug treatment/recovery house

Table 2.

In-depth details of core components of peer-based interventions to support transgender and gender diverse people’s health and healthcare access (n = 40).

Author(s) & Date	Intervention Name	Underlying Theory and/or Evidence-based Intervention(s)	Delivery Modality and Level of Structure	Times Met/Meet and Length	Activities Conducted	Peer Facilitator Characteristics	Facilitator Training and Intervention Fidelity Measures
Altaf et al. (2022)	Not specified	Not Specified	Individual, semi-structureda (peer-led)	One initial session and one follow-up questionnaire	Psychoeducationb Distribution of prevention supplies Linkage to health servicesc Testing	Ages 25 to 55, not otherwise specified	Two half-day trainings on study procedures, ethical considerations, data collection, follow-up, and HIV self-testing practice
Barrington et al. (2021)	Abriena Puertas (AP; Opening Doors)	Not Specified	Individual (psychologist led) structured group, unstructured (peer-led)	Variable, up to 6 contacts with navigator; up to 6 community workshops	Accompaniment Social support Psychoeducation Skill developmentd	Trans women sex workers	Not specified
Blackstock et al. (2021), Walters et al. (2021)	PrEP-UP	Information-Motivation-Behavioral Skills Model	Individual, semi-structured (peer-led)	One 15-minute education session, variable phone follow-up if care linkage requested	Psychoeducation Linkage to health services Assistance meeting SDoHe Distribution of prevention supplies HIV/STI testing Mental health care Linkage to substance use care	1 trans woman and 1 cis woman; shared experience in exchange sex and/or substance use	30 hours of training on participant recruitment, PrEP education and counseling, linkage and navigation strategies, harm reduction, and participant confidentiality Supervision by study’s project manager
Colson et al. (2020)	enPrEP (Enhanced PrEP)	Not specified	Individual, unstructured Group, semi-structured (peer-led)	Variable, median 1 interaction with navigators; median 0 support group meetings; weekly SMS reminders	Psychoeducation Social support Assistance meeting SDoH	Black MSM or trans women	1-month long study training Shadowing other peer navigators Task supervision by PI Support group supervised by licensed psychologist
Cunningham et al. (2018)	LINK LA (Linking Inmates to Care in Los Angeles)	Social Cognitive Theory HIV Continuum of Care	Individual, structured (manualized) (peer-led)	Total 12 in-person sessions including up to 2 HIV care accompaniments and 3 follow-up calls	Psychoeducation Skill development Linkage to health services Assistance meeting SDoH	Black or Latinx with common experiences of participants (e.g. incarceration, living with HIV, substance abuse recovery)	1-week training using detailed manual Daily monitoring, weekly supervision, periodic auditing of records Checklist documenting delivery of each session
Deering et al. (2011)	MAP (Mobile Access Project)	Not specified	Individual, unstructured (peer-led)	Varied	Outreach Safe space to rest, access food Psychoeducation Distribution of prevention supplies (e.g. condoms, lube, syringes)	Not specified	Not specified
Gamariel et al. (2020)	Medecins Sans Frontières (MSF) peer-driven education program and other peer-driven programs available	Not specified	Individual and group, unstructured (peer-led)	Not specified	Outreach Psychoeducation Linkage to health services Distribution of prevention supplies	MSM and trans people	Trained in engaging with participants to promote health service use Trained to do HIV/STI counseling, testing, and referrals
Garofalo et al. (2012)g; Garofalo et al. (2018)	Project LifeSkills	CDC’s Compendium for “Best Evidence” Risk Reduction Criteria Social-ecological Theory	Group, structured (peer-led)	2 hour sessions twice per week for 3 weeks; 4-, 8-, and 12-month follow-up visitsf	Stigma reduction Skill development Psychoeducation Goal development	Trans-identified people	Not specified
Gillard et al. (2022)	Not Specified	Peer support principles	Individual, unstructured (peer-led)	One or more meeting in-patient, one meeting per week for 10 weeks immediately after discharge, one meeting bi-weekly for the following 6 weeks	Social support	People living with mental health problems and who use mental health services	8-week training, 6-hours per week (personal asset mapping, goal setting, discharge recovery, crisis planning)
Hirshfield et al. (2021); Rebchook et al. (2022)	TWEET (Transgender Women Engagement and Entry to Care Project)	Social Learning Social Cognitive Theory	Group, structured (peer-led)	Sessions twice per week, up to 120 minutes, median time in intervention of 18 months, no fixed end time	Psychoeducation Linkage to health services Social support	Trans women, mostly Latina	Attending a minimum of 3 sessions Meeting with intervention staff for individual coaching/technical assistance
Kaplan et al. (2019)	Baynetna (“between us girls”), adapted from TransAction	Not Specified	Group, structured (peer-led)	6 specific 3-hour weekly sessions	Psychoeducation Stigma reduction Skill development	A trans woman	Training, unspecified
Klotzbaugh and Fawcett (2023)	Not specified	Roy Adaptation Model Minority Stress Theory Intersectionality Theory	Group, semi-structured (peer-led)	Bi-weekly, variable engagement over > 5 years	Identity exploration Stigma reduction Safe space Social support Mental health support	A gender minority person of shared identity (groups were separated by identity)	Not specified
Kuhns et al. (2021); Rebchook et al. (2022)	TransLife Care (TLC)	Social Determinants of Health Trauma-informed Client centered Strengths-based Systems theory Harm Reduction	Individual, unstructured (peer-led and non-peer) Group, unstructured (peer-led),	Variable	Linkage to HIV care Social support Safe space Linkage to gender-related care Case management Cash incentive Outreach Assistance meeting SDoH	Trans individuals	Not specified
Lapadula et al. (2023)	Not specified	Not specified	Individual, semi-structured (peer and non-peer-led)	1 survey, 1 test, and post-test follow-up	Testing Psychoeducation Linkage to health services Distribution of prevention supplies	Trans woman	Not specified
Lippman et al. (2022)	Trans Amigas	Social Cognitive Theory Gender Affirmation Model	Individual, structured (peer-led)	9 monthly one-on-one sessions and monthly phone check-ins, variable additional contact	Development of goals Psychoeducation Assistance meeting SDoH Linkage to HIV care Linkage to gender-related care	Trans women living with HIV	Multi-week training on: developing SMART goals, strategies for coping with transphobia, fostering interpersonal dynamics, ethical behavior in research, and personal/ professional boundaries Supervision weekly by a trained psychologist
Martinez et al. (2019)	TIP (Transhealth Information Project)	CLEAR (Choosing Life: Empowerment, Action, Results) Cognitive-Behavioral Theory Social Action Theory	Individual and group, semi-structured (peer-led)	6 specific sessions	Linkage to health services Provision of health services Stigma reduction campaigns Peers taking leadership roles in community Psychoeducation Skill development	Men and women of trans experience, diverse in race and ethnicity	Training, unspecified
Mwango et al. (2022)	Community Impact to Reach Key and Underserved Individuals for Treatment and Support (CIRKUITS), and Zambia Community HIV Epidemic Control for Key Populations (Z-CHECK)	Not specified	Individual, semi-structured (peer-led)	Initial testing, follow-up if being treated	Outreach Linkage to health services Psychoeducation Testing Distribution of prevention supplies	Female sex workers, men who have sex with men, and trans persons	Training in HIV testing, psychosocial counseling Supervised by public health facility staff
Nagot et al. (2022)	Not specified	Not specified	Individual, structured (peer-led)	Initial testing; 2-, 4-, 8-, and 12-week follow up if being treated	Psychoeducation Testing HCV treatment Linkage to health insurance Linkage to addiction care Cash incentive	People who currently or formerly used drugs	Training on good clinical practice, study procedures, risk reduction, and counseling for treatment compliance
Pascom et al. (2016)	Not specified	Not specified	Individual, structured (peer-led)	1 test	HIV testing Linkage to health services (HIV care)	People who shared the identities of the individual being tested and/or shared community	Variable, not specified
Pawa et al. (2013)	Sisters	Not specified	Individual or group, unstructured (peer-led)	Variable	Safe space Psychoeducation Linkage to health services Provision of health services Social support Mental health support Outreach Distribution of prevention supplies	Trans nurse provides HIV testing and counseling at drop-in center, trans community members	Not specified
Rajabiun et al. (2022)	Peer Linkage and Re-engagement Intervention for Women of Color with HIV	Not specified	Individual, unstructured (peer-led)	Variable; average of 6 encounters over the first 3 months	Linkage to health services Case management Care planning Assistance meeting SDoH Skill development	Cis or trans women of color with HIV	40 h of training on HIV and treatment, motivational interviewing, trauma-informed care, harm reduction, documentation, and stigma reduction. Supervision by a licensed behavioral health clinician.
Reback et al. (2019)	A.S.K.-PrEP (Assistance Services Knowledge-PrEP)	ARTAS (Antiretroviral Treatment Access) EBI Social Support Theory Health Belief Model Social Cognitive Theory	Individual, structured (peer-led)	5 sessions over 3 months	Psychoeducation Screening/ assessment Assistance meeting SDoH Readiness for change Linkage to health services Technology-mediated support	Peer navigator, one trans woman and one MSM, both HIV negative and one long-term PrEP user	Not specified
Reback et al. (2021); Rebchook et al. (2022)	The Alexis Project	Social Cognitive Theory Contingency Management, guided by Behavioral Economics	Individual, semi-structured (peer-led)	Variable number of sessions, 18-month intervention	Social support Linkage to health services Assistance meeting SDoH Psychoeducation Skill development Cash incentive	Trans women of color living with HIV	Trained on creating and setting boundaries, writing progress notes, maintaining confidentiality, communication, countertransference and self-care Semimonthly clinical supervision HIV infectious disease medical advisor annual training on HIV care and medical records
Rebchook et al. (2022)	INFINI-T	Syndemic Theory	Individual, semi-structured (peer and non-peer) Group, structured	Variable over 24 months	Linkage to HIV care Referral to services Case management	Trans youth	Not specified
Rebchook et al. (2022)	Howard Brown		Group, semi-structured and unstructured (peer and non-peer-led)	Variable weekly (youth) and bi-weekly (adult)	Medical care provision Needle exchange Insurance counseling Food Safe space	Trans youth and adults	Not specified
Rebchook et al. (2022)	Princess Project	Motivational Enhancement Therapy Motivational interviewing	Individual, structured Group, Structured	6 individual sessions, weekly group	Safe space Psychoeducation Skill development Social support Cash incentive Referral to services Mental healthcare provision	Black/African American trans women	Not specified
Rebchook et al. (2022)	Transactivate	Trans Theoretical Model Strengths-based Perspective	Individual, semi-structured (peer-led)	Variable	Accompaniment Linkage to medical care Cash incentive	Latina trans women	Not specified
Rhodes et al. (2020)	HOLA	HoMBReS and HoMBReS por un Cambio EBIs Social Cognitive Theory Empowerment Theory Social Support Theory	Individual and group, semi-structured (peer-led)	12 months, variable contact	Psychoeducation Readiness for change Stigma reduction campaigns	Chosen based on personal characteristics (e.g. respectful), performance characteristics (e.g. communication), situational characteristics (e.g. time availability)	Trained by 2 Latinx gay men during 4, 4-hour sessions on HIV/STI prevention and care for Latinx sexual and gender minorities; roles, responsibilities, communication and social support Met monthly for 12 months as a group with project coordinator, submit activity logs
Sevelius et al. (2020)	Sheroes	Model of Gender Affirmation	Group, structured (peer-led)	5 weekly sessions Baseline and 3- and 6- month post-intervention surveys	Psychoeducation Social support Stigma reduction Cash incentive	Trans women of color	25 hours of training on the Sheroes intervention Ongoing supervision
Sevelius et al. (2021)	Trans Research-Informed communities United in Mobilization for the Prevention of HIV (TRIUMPH)	Model of Gender Affirmation	Individual, structured (peer and non-peer-led) Group, semi-structured (peer-led)	Variable Baseline and 1-, 3-, 6-, 9-, and 12-month post-intervention surveys.	Psychoeducation Testing Distribution of PrEP Linkage to legal services Linkage to mental health services Social support Outreach Stigma reduction campaigns Hormone provision and maintenance	Trans women of color	“Extensively trained”
Sevelius et al. (2022)	Healthy Divas	Model of Healthcare Empowerment Model of Gender Affirmation	Individual, structured (peer-led) Group, structured (non-peer led)	6 weekly sessions, 1 group session Baseline and 3-, 6-, 9- and 12-month post-intervention surveys	Psychoeducation Skill development Stigma reduction Care planning Social support Linkage to gender-related care Linkage to legal services Linkage to substance use services Cash incentive	Trans women	“Extensively trained”
Sevelius et al. (2023)	Girlfriends Connect	Model of Gender Affirmation	Individual, structured (peer-led) Group, semi-structured (peer-led)	2 individual sessions pre-release, biweekly support group, 3 individual sessions post-release	Needs assessment Social Support Linkage to gender-related care Assistance meeting SDoH Goal development Cash incentive	Transfeminine people of color	Not specified
Soe et al. (2022)	Reach-Recruit-Test-Treat-Retain (RRTTR)	Not specified	Individual and group, semi-structured (peer-led)	Variable	Distribution of prevention supplies Psychoeducation Linkage to health services Testing	Community member, variable	Not specified
Strömdahl et al. (2019)	Testpoint	Not specified	Individual, structured (peer-led)	1–2 tests over the time period the intervention was offered; testing sessions lasted 2.5 hours each	Testing Psychoeducation	LGBTQ + people	Not specified
Subramanian et al. (2013)	Avahan	Not specified	Individual, structured (peer-led)	Variable, from 1 visit to > 4 visits, ideally at least monthly	Outreach Psychoeducation Distribution of prevention supplies Linkage to health services Stigma reduction campaigns/ community mobilization	MSM and trans women	Not specified
Webel (2010)	Positive Self-Management Program (PSMP)	Social Cognitive Theory	Group, structured (manualized) (peer-led)	7, 2-hour sessions	Psychoeducation Skill development Social support	Identified as community leaders by HIV case managers, community leaders, and health care worker	5-day, 26-hours standardized training Mock delivery of two PSMP modules
Willging et al. (2018)	LGBTQ Peer Advocate Intervention	Community Health Worker (CHW) models	Group or individual, unstructured (peer-led)	Variable number of connections, over 6 months	Social support Skill development Linkage to health services Stigma reduction campaigns (with providers)	Peer advocates from LGBTQ communities	4-day training in outreach and education, mental health and substance use, support services, community activities, minority stress, LGBTQ diversity, and rural treatment systems Ongoing mentorship, individually and as a group
Wilson et al. (2021)); Rebchook et al. (2022)	Brandy Martell Project	Critical Race Theory	Individual, unstructured (peer-led and non-peer) Group, structured (peer-led)	Variable number of connections over 12 months	Medical service provision Legal service provision Psychoeducation Skill development Accompaniment	Trans of color	Not specified
Wilson et al. (2021); Rebchook et al. (2022)	TransAccess	Trans-affirming care Self-actualizing services Mindful medicine Harm Reduction Community centered Radical healthcare	Individual, unstructured (peer and non-peer-led)	Variable number of connections over 12 months	Case management Mental health services Psychoeducation Medical service provision Accompaniment	Asian Pacific Islander, Trans women	Not specified
Young et al. (2022)	Sex Now	Not specified	Individual, structured (peer-led)	1 test 1 follow-up phone call with results	DBS testing	GBT2Q-identified	Site coordinators received in-person training in DBS testing, then trained their local DBS volunteer collectors

^a Semi-structured: specific content, delivered flexibility

^b Psychoeducation included topics of: HIV and STIs including prevention and care (n = 9), recent client experiences of violence (n = 1), gender transition (e.g. hormone therapy) (n = 2), mental health/wellness (n = 2), problem-solving (n = 1)

^c Linkage to healthcare included referrals, appointment scheduling, accompaniment, liaising with providers)

^d Skill development included skills of: coping with stigma and discrimination (n = 1), accessing care (n = 1), self-advocacy (n = 3), communication (n = 1), leadership (n = 1), employment skills (n = 1)

^e Assistance meeting social determinants of health (SDoH) including: transportation, housing, generally

^f Technology-mediate support: GeoPass (develop a mobile passport that incorporates personalized participant goals and other features to facilitate and motivate accessing of services, adherence support text messages

^g Description of the LifeSkills intervention can be found in Garofalo et al. (2012).

Sample characteristics

With respect to geography, a large proportion of the interventions (n = 17/40, 42.5%) were conducted in large urban centers in the U.S., such as New York (e.g. Blackstock et al., 2021), San Francisco (e.g. Sevelius et al., 2020), and Los Angeles (e.g. Cunningham et al., 2018). One intervention (2.5%) was carried out exclusively in a rural part of the U.S. (Willging et al., 2018), while six interventions (15.0%) took place in the U.S. with details unspecified such as that by Klotzbaugh and Fawcett (2023) which took place in Southwestern U.S. for a total of 24/40 (60.0%) of interventions U.S.-focused. The remaining interventions (n = 16/40, 40.0%) took place outside of the U.S. in other parts of North America, including Canada (Deering et al., 2011; Young et al., 2022); Caribbean/Central/South America including Dominican Republic (Barrington et al., 2021) and Brazil (Lippman et al., 2022; Pascom et al., 2016); Europe including England (Gillard et al., 2022), Italy (Lapadula et al., 2023), France (Nagot et al., 2022) and Sweden (Strömdahl et al., 2019); Africa including Mozambique (Gamariel et al., 2020) and Zambia (Mwango et al., 2022); Middle East including Lebanon (Kaplan et al., 2019); and, East/South East Asia including Pakistan (Altaf et al., 2022), Thailand (Pawa et al., 2013; Soe et al., 2022), and India (Subramanian et al., 2013).

Just over half of 40 interventions (n = 23, 57.5%) focused exclusively on TGD people, of which 17/23 (73.9%) focused on trans women/persons of transfeminine experience (e.g. Hirshfield et al., 2021). Six interventions grouped trans women with men who have sex with men (MSM) (e.g. Colson et al., 2020), while four interventions combined trans women and cis women within a women’s study (e.g. Rajabiun et al., 2022). Other interventions grouped TGD people among samples of people who have been incarcerated, LGBTQ + people, people with mental health challenges, or people living with HIV. Among those interventions that grouped TGD people with another population, within nine interventions TGD participants comprised less than 15% of the total sample, with the TGD sample comprising as little as 0.09% (Walters et al., 2021).

Study designs and outcomes studied

Of the 36 studies documenting 40 interventions, most were fully or partially quantitative (n = 33/36, 91.7%), including 14/36 (38.9%) quasi-experimental (Altaf et al., 2022; Barrington et al., 2021; Blackstock et al., 2021; Deering et al., 2011; Hirshfield et al., 2021; Kaplan et al., 2019; Kuhns et al., 2021; Pawa et al., 2013; Rajabiun et al., 2022; Reback et al., 2019; Sevelius et al., 2021; Subramanian et al., 2013; Wilson et al., 2021) predominantly pilot interventions with pre-/post-test design, nine (25.0%) descriptive (Lapadula et al., 2023; Martinez et al., 2019; Mwango et al., 2022; Nagot et al., 2022; Pascom et al., 2016; Rebchook et al., 2022; Soe et al., 2022; Strömdahl et al., 2019; Willging et al., 2018) and ten (27.8%) randomized controlled trials (RCTs) (Colson et al., 2020; Cunningham et al., 2018; Garofalo et al., 2012, 2018; Gillard et al., 2022; Lippman et al., 2022; Rhodes et al., 2020; Sevelius et al., 2020, 2022, 2023; Webel, 2010). For an example of a quasi-experimental study, Reback et al. (2021) conducted a cohort study with 6-, 12-, and 18-month follow-up examining HIV care (e.g. linkage to care) and HIV health (e.g. viral load). With respect to a quantitative descriptive study, Mwango et al. (2022) drew on retrospective analysis of aggregate program data to document the proportion of those testing positive for HIV linked to HIV care and those testing negative initiating PrEP. Regarding an RCT, Cunningham et al. (2018) compared a peer navigation intervention with standard transitional case management on HIV health (e.g. viral suppression) and HIV care (e.g. retention and ART adherence) among other outcomes. Three (8.3%) studies were fully qualitative (Gamariel et al., 2020; Klotzbaugh & Fawcett, 2023; Young et al., 2022) and four (11.1%) included both quantitative and qualitative elements (Barrington et al., 2021; Blackstock et al., 2021; Garofalo et al., 2012, 2018; Willging et al., 2018).

The vast majority of studies included HIV outcomes (n = 30/36, 83.3%). Among the studies that included a quantitative component, the most frequently assessed outcomes were related to HIV health, including viral suppression/CD4 count (n = 6) (e.g. Kuhns et al., 2021), engagement in HIV care, including ART uptake (n = 11) (e.g. Lippman et al., 2022), HIV/STI testing (n = 9) (e.g. Rhodes et al., 2020) and PrEP uptake/adherence (n = 6) (e.g. Lapadula et al., 2023). A number of studies (n = 7) (Altaf et al., 2022; Barrington et al., 2021; Blackstock et al., 2021; Kaplan et al., 2019; Lippman et al., 2022; Sevelius et al., 2023; Subramanian et al., 2013) examined acceptability of the intervention. Less frequently studied outcomes included utilization of other types of healthcare, such as primary care, treatment of hepatitis C, and substance use treatment, condom use, and mental health outcomes. Notably, only two studies measured gender affirmation outcomes (Hirshfield et al., 2021; Sevelius et al., 2023). Specifically, Hirshfield et al. (2021) measured access to legal gender affirmation and Sevelius et al. (2023) examined access to gender-affirming medical care including hormones and gender-affirming surgeries.

Core components of interventions

Just over half of the interventions (n = 23/40, 57.5%) specified one or more underlying theory and/or evidence-based intervention from which the peer-based intervention was adapted. Among those interventions specifying an underlying theory, social cognitive theory was the most commonly utilized (n = 7) (e.g. Hirshfield et al., 2021). The next most commonly applied theoretical approach was that of the gender affirmation model (n = 6) (e.g. Lippman et al., 2022), though that theory was predominantly applied by Sevelius and colleagues in multiple interventions. Other foundational theories applied included critical social theories (e.g. intersectionality, critical race theory), stress-related theories (e.g. minority stress theory, syndemics theory), health behavior change theories (e.g. information-motivation-behavioral skills [IMB] model, social action theory, motivational interviewing, and transtheoretical model), and social work-related theories (e.g. social ecological/systems theory, strengths-based/client-centered/trauma-informed theories) (Table 2). Four U.S. Centers for Disease Control and Prevention (CDC)-recognized and one Substance Abuse and Mental Health Services Administration (SAHMSA)-approved evidence-based intervention also informed the development of these peer-based interventions (Garofalo et al., 2012, 2018; Martinez et al., 2019; Reback et al., 2019; Rhodes et al., 2020).

Many interventions (n = 18/40, 45.0%) were delivered in a one-on-one setting, with nearly as many (n = 15/40, 37.5%) delivered using a combination of individual and group modalities (e.g. Rajabiun et al., 2022). A smaller proportion (n = 7/40, 17.5%) were delivered using a group format only (e.g. Garofalo et al., 2012, 2018). Just over one-third of the interventions (n = 15/40, 37.5%) were delivered entirely in a standardized/structured manner (e.g. Cunningham et al., 2018). Others were delivered in a semi-structured manner, whereby specific content was provided but delivered flexibly (n = 10/40, 25.0%) (e.g. Klotzbaugh & Fawcett, 2023). A minority of interventions were delivered in an entirely unstructured approach (n = 8/40, 20.0%) (Wilson et al., 2021) or using a combination of delivery approaches (n = 7/40, 17.5%) (Rebchook et al., 2022). Frequency of contact varied by program, with some groups occurring as much as twice a week (n = 2) (Garofalo et al., 2012, 2018; Hirshfield et al., 2021) or once a week (n = 6) (Gillard et al., 2022; Kaplan et al., 2019; Rebchook et al., 2022; Sevelius et al., 2020, 2022) and others requiring peer leaders to make contact with recipients at least once a month (n = 2) (Lippman et al., 2022; Reback et al., 2019). The length of time of interventions also varied significantly, ranging from one session (n = 8) (e.g. Pascom et al., 2016) to variable over three, six or 12 months. In group settings, sessions typically lasted around two to three hours.

Intervention activities most commonly included psychoeducation (n = 29/40, 72.5%) (e.g. Sevelius et al., 2020) and linkage to health services (n = 22/40, 55.0%) (e.g. Subramanian et al., 2013), with most frequent emphasis on HIV/STI testing and/or care (n = 13/40) (e.g. Strömdahl et al., 2019). Provision of social support was also common (n = 15/40, 37.5%) (Gillard et al., 2022), and almost one-third included skill development (n = 12/40, 30.0%) (Garofalo et al., 2012, 2018). Other, less common, intervention components included assistance meeting social determinants of health, accompaniment to appointments, identity exploration, goal development and planning, outreach, provision of a safe space, distribution of prevention supplies, screening/assessment, readiness for change interventions, mental health support (e.g. counseling), technology-mediated support, cash incentives, stigma reduction campaigns/community mobilization, and promotion of peers taking leadership roles in community. Only six interventions involved linkage with gender affirmation services (medical transition, hormones, legal services).

All but one interventions specified the characteristics of the peers (e.g. sociodemographic and/or lived experiences and/or other qualifications) (Deering et al., 2011). Studies specifying peer facilitator characteristics suggested that peer facilitators were chosen based on shared characteristics with participants, whether it be race/ethnicity, gender identity, sexual orientation, living with HIV, or past/current experiences of incarceration, sex work, substance use, or a combination of these characteristics. Most interventions explicitly specified working with trans-identified peer facilitators (n = 29/40, 72.5%) with the exception of those who mentioned inclusion of LGBTQ + people broadly (Strömdahl et al., 2019; Willging et al., 2018; Young et al., 2022), peers identified as community leaders and/or possessing specific skills (Rhodes et al., 2020; Webel, 2010), unspecified exactly which identities but shared identities (Pascom et al., 2016; Soe et al., 2022), people who currently or formerly use(d) substances (Nagot et al., 2022), and people living with HIV with mental health experience (Gillard et al., 2022).

Just over half of the interventions detailed how/if peers were trained (n = 21/40, 52.5%). Among those providing these details, the length of training ranged significantly, from two half-day trainings (Altaf et al., 2022), to one week (Cunningham et al., 2018), to 48 h over a 6-week period (Gillard et al., 2022) with seven interventions including peer supervision (e.g. Mwango et al., 2022).

Intervention effectiveness

Most RCTs showed positive impacts for peer-led interventions compared to a standard of care or control, on at least some outcomes, including improved HIV health (Cunningham et al., 2018), HIV care engagement (Cunningham et al., 2018; Lippman et al., 2022; Sevelius et al., 2022), HIV testing (Rhodes et al., 2020), or reduced sexual risk practices such as condomless sex (Garofalo et al., 2012, 2018; Sevelius et al., 2020) (Table 1). With respect to other outcomes, findings were more mixed. For example, Colson et al. (2020) found no statistically significant difference between peer navigation and standard of care for PrEP adherence, Gillard et al. (2022) found no statistically significant difference across arms with respect to psychiatric hospital readmission, and while Webel (2010) saw greater increases in quality of life among cis and trans women living with HIV participating in a peer-based intervention compared to a control group, they also reported no significant difference between groups with respect to symptom intensity and medication adherence. Multiple studies showed decreased engagement and retention in care and/or intervention over time.

The quasi-experimental studies also showed promising results for involvement in a peer-based intervention with respect to HIV care engagement (Barrington et al., 2021; Kuhns et al., 2021; Rajabiun et al., 2022; Wilson et al., 2021), HIV testing (Pawa et al., 2013), and sexual risk practices (Pawa et al., 2013). Quasi-experimental studies showed a broader range of positive associations between peer-based interventions and outcomes, including PrEP initiation/adherence (Sevelius et al., 2021), substance use treatment (Deering et al., 2011), and mental health (Kaplan et al., 2019). Hirshfield et al. (2021) showed that being the Peer Leader can have an equally positive impact on an individual’s health above simple engagement in a peer program. Specifically, becoming a Peer Leader was associated with improved engagement in HIV care, decreased viral load, and increased CD4 count (Hirshfield et al., 2021). Subramanian et al. (2013) found a significant decrease in syphilis over participation in two rounds of cross-sectional bio-behavioral surveys conducted with high-risk MSM and trans women participating in a peer navigation HIV prevention program. However, neither an increase in condom use nor HIV decrease were statistically significant (Subramanian et al., 2013).

Considering last the primarily descriptive quantitative and qualitative studies, findings from one qualitative study suggested that peer-driven models of engagement are appreciated, but their availability is limited (Gamariel et al., 2020). Qualitative results of the mixed methods evaluation conducted by Willging et al. (2018) suggested preliminary evidence for the intervention’s effectiveness to enhance social support and self-advocacy of participants.

Findings from the quantitative descriptive study by Martinez et al. (2019) documented the number of trans people reached (e.g. 80 trans people in 2017), and in particular trans people of color (e.g. 97% of 80 participants), by a peer-led intervention. These and other descriptive studies suggest acceptability of peer-based interventions among TGD populations.

Discussion

The aim of this scoping review was to explore the existing literature on peer-based interventions that had been inclusive of or specifically tailored to TGD populations. In doing so, our objective was to identify and document knowledge gaps in the literature, including gaps in diversity of participants across sociodemographic characteristics and geography, the outcomes addressed in the interventions, and the specific activities used in the interventions to address the outcomes. To our knowledge, ours is the first scoping review to-date that describes the extent to which peer-based interventions are utilized for TGD people.

Results of this review largely demonstrate positive support for peer-based interventions for a variety of health outcomes, particularly HIV health and HIV care engagement. The RCT results are particularly promising, though only half were TGD-specific. Given that an estimated 14% of trans women in the U.S. are living with HIV (Becasen et al., 2019) and trans women have 49 times the odds of living with HIV compared to cis persons, globally (Baral et al., 2013), interventions to improve HIV-related outcomes are paramount. However, in focusing explicitly on HIV, extant research fails to address other critical health needs of TGD people. Perez-Brumer et al. (2018) note that the overwhelming focus on HIV in the TGD health literature has not only “overshadow[ed] other healthcare needs but has also manifested in discrimination in healthcare settings through an assumption that all trans patients have HIV, as well as fewer affirming services available to trans patients who do not have HIV” (para. 3). Moreover, this hyper-focus on HIV or other STIs both reinforces stigma with respect to trans women (Bauer & Hammond, 2015), and invisibility with respect to holistic needs and experiences.

Our scoping review highlights a critical need for additional research on this topic. In particular, the findings of this scoping review suggest a need for: (1) peer-based interventions that expand beyond HIV health, particularly inclusive of mental health and chronic disease outcomes; (2) peer-based interventions that address gender-diversity within TGD populations, uniquely considering the different needs of trans men, trans women, and nonbinary people, and those at the intersection of marginalized identities across race/ethnicity; and, (3) peer-based interventions that are grounded in a framework of and measure outcomes related to gender affirmation. The subsequent paragraphs detail each of these gaps.

With respect to gaps in studies that examine peer-based interventions focused on non-HIV outcomes, there are shortcomings in the peer intervention literature related to mental health outcomes, which is an urgent area of need. Indeed, a robust body of literature suggests that TGD populations experience a high burden of mental health issues (e.g. anxiety, depression) (Reisner et al., 2016; Rich et al., 2020), due, in part, to stigma and discrimination (White Hughto et al., 2015). In a 2015 national survey of nearly 28,000 U.S. trans adults, 39% of respondents reported that they were experiencing serious psychological distress, as compared to 5% of the general population (James et al., 2016). Moreover, 40% of respondents shared that they had attempted suicide in their lifetime, as compared to just 4.6% of the general U.S. population. There is a robust body of literature with regards to the general population that suggest the efficacy of peer-based interventions for depression (Pfeiffer et al., 2011; White et al., 2020). Moreover, a scoping review identified peer support as a protective factor against suicide risk in TGD populations (Kia et al., 2021). Future research with TGD populations could draw on the robust non-TGD-specific mental health peer-based intervention literature and the corroborative TGD-specific peer support social research (Kia et al., 2021, 2023) to develop and evaluate population-specific application of mental health interventions.

Apart from mental and sexual health, findings from a recently published systematic review and narrative synthesis showed prevalence of multiple chronic conditions among TGD persons comparable or higher than the general population, suggesting that addressing other chronic conditions—beyond STIs and mental health—through peer-based interventions may be warranted. For instance, one study showed that trans men had over double the odds of myocardial infarction relative to cis men, and trans women had double the odds of myocardial infarction relative to cis women (Rich et al., 2020). Another study documented a 2.3-fold higher prevalence of type 1 diabetes mellitus in trans patients (Defreyne et al., 2017). These chronic health disparities are not surprising given documented associations between chronic stress related to stigma and discrimination and health outcomes (Beckie, 2012). However, chronic disease management may also be supported through peer-based intervention, as meta-analyses have documented positive clinical impacts of peer support for diabetes (Qi et al., 2015) and hypertension (Krishnamoorthy et al., 2019). This evidence calls to question as to why no literature about peer-based interventions for chronic disease outcomes exist for TGD populations.

Beyond the narrow focus on HIV, another major gap is that of those studies which were trans-specific, all focused on trans women, and none on TGD people of other identities. This renders invisible differences within TGD communities and does not affirm TGD peoples’ genders or the specific intervention components the TGD population overall, nor specific sub-sets of said population, may benefit from. In particular, this literature erases the needs and experiences of trans men and nonbinary people, despite the evidence that differences exist (Cicero et al., 2020; Clark et al., 2018; Rich et al., 2017). For example, there is qualitative evidence to suggest trans men may experience both general (shared) barriers to STI/HIV testing uptake with trans women as well as some specific barriers, such as a lack of provider knowledge about trans men’s sexual practices and provider perceptions of low risk and active dissuasion from seeking testing (Rich et al., 2017).

Finally, scholars, activists, and service providers alike have called for gender affirmation as a framework for addressing health disparities, in addition to underscore the essential aspect of partnering with TGD communities (Reisner et al., 2016). Gender affirmation, a process whereby a person receives recognition and support for their gender identity and expression (Sevelius, 2013), is a social determinant of health for TGD people (Reisner et al., 2016). Gender affirmation can be enhanced through social (e.g. use of a new name, gender pronoun), psychological (e.g. self-love/affirmation), legal (e.g. updating legal identity documents), and/or medical processes (e.g. hormone therapy, gender-affirming surgeries) (Reisner et al., 2016). Although not all TGD people access medical transition, professional organizations recognize that access is medically necessary to support the health and well-being of those who require it (Coleman et al., 2022) with many positive psychosocial effects including reduced suicidal ideation, depression, substance use and stigma, as well as increased quality of life and resilience (Bauer et al., 2015; Crosby et al., 2016; Lindqvist et al., 2017; White Hughto & Reisner, 2016). Thus, it is a notable gap that few studies explicitly made mention of increasing access to gender affirmation, likely exacerbated by the fact that not all interventions were TGD-specific. Specifically, Hirshfield et al. (2021) mentioned increasing access to legal gender affirmation and providing education about medical gender affirmation. Pawa et al. (2013) indicated providing information on medical gender affirmation, specifically, hormone therapy. Reback et al. (2021) provided information about hormone misuse as well as medical advice and provision of care referring to the co-administration of antiretroviral therapy and hormones. Sevelius et al. (2023) both referred participants for gender-affirming medical care and followed up on this access. By centering gender affirmation, future development of peer-based interventions could both address root causes of health inequities and make meaningful contributions to the everyday lived reality of TGD people and communities.

The few studies that focused exclusively on trans women or TGD people did not always attend to intersecting identities, particularly race. This is critical given the ways that intersecting identities uniquely contribute to TGD people’s experiences in healthcare settings and beyond. For example, a study exploring trans people of color’s experiences in the healthcare setting via individual interviews and focus groups found that even in LGBTQ+-affirming spaces, some participants still encountered discrimination in the form of racism (Howard et al., 2019). Findings of the aforementioned 2015 U.S. Transgender Study showed that while 19% of the total sample of the were refused care, overall, among White TNB individuals, 17% had been denied care, while the proportion was higher for all groups of people of color, with up to 36% of Native participants having been denied care (James et al., 2016).

There was variety with regards to the peer-based interventions’ modalities; including individual, group, and a mixture of individual and group; as well as the degree of structure. As intervention design should be tailored to best meet the intervention aims/objectives and needs of the participants, there is no “one size fits all” approach for designing a peer-based intervention. Nevertheless, meta-analyses of peer-based interventions for other issues may also be used to inform the structure of future peer-based interventions. A meta-analysis of peer-led interventions to reduce unprotected anal intercourse (UAI) among MSM found that more structured interventions with weekly sessions did reduce overall UAI (Ye et al., 2014). Another meta-analysis on peer support interventions with cardiovascular disease risk factors saw more success in longer term interventions of at least 6 months that relied on structured sessions in conjunction with one-on-one calls from peers (Patil et al., 2018). A meta-analysis on peer-led interventions to increase HIV testing found that interventions relying on the Internet and mobile outreach had a positive impact on HIV testing (Shangani et al., 2017). There is also incredible variability within which, how, or if interventions were informed by an underlying theory, who is considered a peer, and training. This variability further limits our ability to draw conclusions about effective elements of peer-based interventions. Future rigorous research that tests these dimensions is desperately needed to avoid waste of resources in the ongoing study and implementation of these interventions.

While we present an in-depth scope of the existing, albeit limited, literature about peer-based interventions focused on health and healthcare access that included TGD people, there are several notable limitations within the included studies, one of which was the relatively small sample size of TGD people included in some non-TGD-focused studies. While we required at the very least that studies explicitly reported the gender breakdown of their participants, we did not require disaggregated data beyond that. This raises several questions to explore in future studies, such as: when TGD persons are included in non-TGD specific interventions, is the efficacy of the intervention equivalent between cis and TGD persons? Moreover, while some non-TGD-specific interventions still explicitly employed TGD peers, approximately one-quarter of included studies did not explicitly mention having TGD-identified peers and instead had peers with other shared experiences to participants (e.g. HIV status, substance use history). Thus, another question remains as to the extent to which TGD persons may have experienced these interventions to be truly peer-based. Given that when TGD persons are included in non-TGD studies their specific experiences may go overlooked, the most meaningful studies are those that are TGD-specific. The results of non-TGD-specific peer-based interventions, particularly those that did not employ a TGD-identified peer, should be interpreted with caution. The study search, in and of itself, was limited by the focus on studies published in English and the inclusion of peer-reviewed articles without assessing the evidence in grey literature. The non-consideration of grey literature may unintentionally convey a lack of popularity or importance of peer-based interventions for TGD populations, as these types of programs are widespread, but may not have been rigorously evaluated and published in scientific literature. From an intersectional perspective, we highlighted the sociodemographic characteristics across race, gender, and other experiences (e.g. incarceration, HIV status) of study participants as described in the inclusion criteria of included studies (e.g. Black trans women, Colson et al., 2020). However, given the breadth of our scoping review, we did not systematically extract detailed data on race/ethnicity nor other sociodemographic characteristics (e.g. socioeconomic status) of study participants from the Results sections of included articles. While drawing on inclusion criteria data alone we were able to identify that few studies focused explicitly on trans men and/or nonbinary persons, nor racial/ethnically or otherwise diverse sub-populations, a future review could dig deeper with respect to intersectional considerations by extracting more detailed sociodemographic data from study findings.

Another limitation was the lack of consistent study outcomes found in our review. While most outcomes were related to health, especially those related to sexual health, those health outcomes were measured very differently on intrapersonal and interpersonal levels. Finally, studies identified in our scoping review were geographically limited to more urban areas with greater acceptance of LGBTQ + individuals and communities, with only three studies conducted in the U.S. South. This reflects the state of TGD-focused research more generally, which has predominantly been conducted in urban areas, and, therefore, skews extant knowledge toward urban-residing trans communities (Knutson et al., 2018). Theoretically, peer-based interventions may have a greater impact in places that are less accepting of LGBTQ + individuals and communities, or places with limited resources, and future research should take this into consideration. For example, the US South, although home the nation’s largest TGD population, provides almost no legal protections in healthcare, education, housing, or employment (Herman et al., 2022; Movement Advancement Project, n.d.). As mentioned, TGD human rights are under attack globally. Peer-based interventions are not a panacea for the deplorable violations of human rights against TGD people, nor will they directly address systemic anti-trans and intersecting stigmas. Indeed, TGD peer support scholars caution against overburdening a marginalized community with the onus to provide their own community’s care, in the absence of larger structural change and institutional accountability for TGD affirmation (Johnson, 2022; Kia et al., 2021).

Although promising in their effectiveness, limited peer-based interventions have been developed and/or evaluated that are specific to TGD people and/or tailored to sub-groups (e.g. trans men and nonbinary people). Grouping TGD people with other communities (e.g. MSM), may lead to specific needs, such as gender affirmation, being overlooked. Studies are urgently need that expand this literature beyond HIV to address holistic health needs and healthcare access barriers among TGD communities.

Funding Statement

The author(s) reported there is no funding associated with the work featured in this article.

Disclosure statement

The authors have no conflicts of interest to disclose.