Sexual Health Advocacy for Guys (SHAG): a randomized trial of the impact of a text-messaging program on HIV incidence and STI testing among a national sample of sexual minority cisgender adolescent and young adult men.
Ybarra M, Feaster D, Garofalo R, Bull S • Trials • 2025
This paper describes the protocol for the first randomized controlled trial with a national sample of cisgender sexual minority adolescent boys and young men ages 13-22 exploring the efficacy of a text messaging-based intervention in increasing HIV and STI testing, and PrEP and PEP use.
Key Findings
Background
Substantial disparities in STIs including HIV exist among sexual minority boys and young men, and effective prevention programs do not consistently include younger sexual minority men.
The paper identifies a gap in HIV and STI prevention programs that include access to pre-exposure prophylaxis (PrEP) medication for younger sexual minority men.
Prior text-messaging programs for HIV prevention have been associated with increases in HIV testing among sexual minority adolescent boys.
These prior programs have not incorporated a focus on PrEP or STIs beyond HIV.
Methods
The SHAG trial is designed as a two-arm randomized controlled trial with 1:1 allocation comparing a text messaging-based HIV and STI prevention intervention to a generic healthy lifestyle control program.
The study uses a superiority design comparing the text messaging intervention to a 'healthy lifestyle' control arm with content focused on promoting self-esteem.
The trial is registered at ClinicalTrials.gov (NCT06230367), with a registration date of 1/29/2024.
The sample includes cisgender sexual minority adolescent boys and young men aged 13-22 years recruited from a national sample.
The study is described as the first RCT with a national sample of this population.
Methods
Primary outcomes of the SHAG trial include HIV and STI testing rates, PrEP and PEP use, and HIV incidence.
Outcomes include testing for HIV and other STIs (beyond HIV), increasing PrEP use, increasing PEP use, and HIV incidence.
Generalized linear models will be used to estimate treatment effects on primary study outcomes.
Longitudinal models estimated based on Generalized Estimating Equations (GEE) are specified to examine effects over time.
Mediation will be assessed based on a product of coefficients approach with bootstrapped standard errors.
Conclusions
The trial is designed to inform the scalability of text messaging programs for sexual health promotion and at-home STI testing, and to demonstrate impacts of a behavioral health intervention on HIV incidence.
The paper notes the program includes a focus on at-home STI testing.
Findings are intended to inform scalability of text messaging-based sexual health promotion.
The study aims to demonstrate impacts of a behavioral health intervention on HIV incidence specifically in sexual minority adolescent and young adult men.
What This Means
This paper describes the study design and protocol for a clinical trial called SHAG (Sexual Health Advocacy for Guys), which is testing whether a text message-based program can help reduce HIV and other sexually transmitted infections (STIs) among gay, bisexual, and other sexual minority young men and teenage boys aged 13 to 22 across the United States. The trial randomly assigns participants to either receive text messages focused on HIV and STI prevention — including information about medications like PrEP (pre-exposure prophylaxis, a pill that prevents HIV) and PEP (post-exposure prophylaxis) — or to a comparison group receiving general healthy lifestyle messages. The study will track whether participants get tested for HIV and other STIs, whether they start using PrEP or PEP, and whether any participants acquire HIV.
This research addresses an important gap because young sexual minority men experience disproportionately high rates of HIV and other STIs, yet most existing prevention programs either don't reach this younger age group or don't cover the full range of prevention tools like PrEP. Previous text-messaging programs showed promise in increasing HIV testing, but none had incorporated PrEP education or broader STI prevention for this population. The SHAG trial is notably the first national randomized controlled trial focused specifically on sexual minority cisgender boys and young men in this age range.
This research suggests that if the text-messaging intervention proves effective, it could offer a low-cost, easily scalable way to deliver sexual health education and connect young sexual minority men to prevention services — including at-home STI testing — without requiring them to visit a clinic. The results will help inform how such programs might be expanded more broadly across the country.
Ybarra M, Feaster D, Garofalo R, Bull S. (2025). Sexual Health Advocacy for Guys (SHAG): a randomized trial of the impact of a text-messaging program on HIV incidence and STI testing among a national sample of sexual minority cisgender adolescent and young adult men.. Trials. https://doi.org/10.1186/s13063-024-08540-9