NIH terminated funding for this project stating "This award no longer effectuates agency priorities."

This project seeks to test the efficacy of a couples-based HIV prevention program in large-scale randomized controlled trial (RCT) to reduce HIV risk among transgender woman and their partners. This project involves enrolling a racially diverse sample of transgender women and their partners and randomizing 50 couples to either the couples-based HIV prevention intervention or an enhanced standard of care (SOC) control condition. Couples will be followed quarterly over 12-months. Analysis of study outcomes will utilize both individual- and dyadic-level data. The primary outcome is a composite measure of risk for HIV transmission which encompasses validated behavioral indicators of HIV risk as well as biomedical confirmation of viral suppression and PrEP adherence.

Transgender women (trans women; individuals with a feminine and/or female gender identity who were assigned male at birth) are disproportionately affected by HIV. One of the most consistently reported contexts for HIV transmission among trans women is within a primary partnership. In this partnership context, trans women report low condom use, difficulty disclosing their HIV status and negotiating HIV prevention strategies, poor communication about whether they permit sex outside of the relationship, and low rates of routine HIV testing. Likewise, research among males who have sex with trans women has found high HIV prevalence, inconsistent condom use with trans women, and low engagement with HIV prevention services.

For the past 10 years the investigators have conducted research to identify intervention targets for reducing HIV transmission in trans women and their partner using qualitative, survey, and intervention adaptation methodologies. Based on these conceptual and empirical understandings of HIV transmission in these dyads, the investigative team developed and pilot tested the first known couples-based HIV prevention program for trans women and primary partners (called "Couples HIV Intervention Program" or CHIP). CHIP was feasible, acceptable, and produced significant reductions in condomless sex acts with primary and casual partners and in number of casual partners at 3-month follow-up compared to a control group.

The project seeks to test the efficacy of the CHIP intervention on reductions in a Composite Risk for HIV (CR-HIV) outcome. CR-HIV is a binary indicator of couple HIV risk using validated measures of sexual behavior (defined as condomless anal or vaginal sex with a serodiscordant or unknown HIV status primary or outside partner), as well as PrEP use among HIV-negative participants and viral suppression among HIV-positive partners. The study involves two-arm prospective RCT in which 50 trans women and their partners (100 participants) will complete a Baseline assessment and then complete assessments every 3 months for 12 months. Recruitment and study activities will occur in San Francisco, California.

Inclusion Criteria:

• Age 18 or older
• Self-report that they are in emotional and/or sexual relationship for at least three months
• One partner must identify as a trans women (assigned the male gender at birth but identify as female or as a trans woman)
• Both partners must have engaged in condomless sex within the past 6 months with any partner
• Able to provide informed consent
• Speak and read English

Exclusion Criteria:

• Currently psychotic, suicidal, or manic
• Either partner reports that participating in the study would cause them physical harm

We will compile structured de-identified datasets and can make them available for additional/secondary data analyses. For data sharing, the research team will follow the "standards for privacy of individually identifiable health information." Participants' records and results will not be identified. No contact information will be included in any archived datasets.

104 individuals (52 couples) were enrolled; the results are presented at the individual-level. Since participants were recruited as dyads, tests for differences in baseline characteristics between intervention and control conditions were adjusted for non-independence in the data due to clustering at the couple level.

One year