Using stated preference methods to design gender-affirming long-acting PrEP programs for transgender and nonbinary adults.

Integrating gender-affirming care with biomedical HIV prevention could help address the disproportionate HIV risk experienced by transgender and nonbinary (trans) adults. This discrete choice experiment assesses and identifies the most important programming factors influencing the decisions of trans adults to use injectable long-acting HIV pre-exposure prophylaxes (LA-PrEP). From March to April 2023 n = 366 trans adults in Washington state chose between four different choice profiles that presented hypothetical programs (each comprised of 5 attributes with 4 levels). We analyzed ranked choice responses using a mixed rank-ordered logit model for main effects. Respondents preferred to receive LA-PrEP from a gender-affirming care provider and a co-prescription for both oral and injectable hormones. Trans adults strongly favored 12-month protection and injection in the upper arm. No strong preferences emerged surrounding the type of health facility offering the gender-affirming LA-PrEP program. Our findings show that integrating and leveraging gender-affirming health systems, inclusive of medical services such as hormone therapy, with HIV biomedical products like LA-PrEP is strongly preferred and influential to trans adults' decision to use LA-PrEP. Leveraging choice-based design experiments provides informative results for optimizing gender-affirming LA-PrEP programming tailored to trans adults.