Incentivizing Adherence to Gender-Affirming PrEP Programs: A Stated Preference Discrete-Choice Experiment among Transgender and Gender Nonbinary Adults

ObjectivesTransgender (trans) people have disproportionately high HIV risk, yet adherence to preexposure prophylaxis (PrEP) remains low in this population. We aimed to determine which factors matter most in the decision of HIV-negative transgender adults to adhere to long-acting injectable PrEP (LA-PrEP), and the acceptability of providing incentives conditional on LA-PrEP program engagement.MethodsFrom March to April 2023, 385 trans adults in Washington State completed a discrete-choice experiment (DCE) eliciting preferences for a conditional economic incentive program that would provide free LA-PrEP and gender-affirming care during bimonthly visits. We used the best-best preference elicitation method across 2 hypothetical programs with an opt-out option. Program attributes included incentive format and amount, method for determining PrEP adherence, and type of hormone co-prescription. We used a rank-ordered mixed logit model for main results and estimated respondents' marginal willingness to accept each program attribute. We plotted the probability of choosing an incentivized LA-PrEP program over a range of respondent characteristics.ResultsThe optimal program design would 1) deliver incentives in cash, 2) confirm PrEP adherence via blood testing, 3) provide counseling in person, and 4) provide prescriptions for injectable gender-affirming hormones. From a maximum incentive amount of $1,200/year, respondents were willing to forgo up to $689 to receive incentives in cash (instead of voucher) and up to $547 to receive injectable (instead of oral) hormones. The probability of choosing a hypothetical program over no program waned as adults aged (>40 y) and as income increased (>$75,000/y).ConclusionsConditional economic incentives are likely acceptable and effective for improving LA-PrEP adherence, especially among younger trans adults with fewer financial resources. A randomized trial is needed to confirm the DCE's validity for predicting actual program uptake.HighlightsGender-related stigma, economic barriers, and medical concerns about hormone interactions can keep transgender (trans) adults from engaging in HIV prevention behaviors.Combining gender-affirming care with conditional economic incentives may help reduce present bias and increase trans persons' motivation to adhere to long-acting injectable preexposure prophylaxis (LA-PrEP).From a maximum yearly incentive of $1,200, trans discrete-choice experiment respondents were willing to forgo up to $689 to receive a cash (rather than voucher) incentive and up to $547 to receive co-prescriptions for injectable (rather than oral) hormones as part of a hypothetical HIV prevention program.The probability of choosing an LA-PrEP program over no program begins to wane as adults age (>40 y) and as annual income increases (>$75,000/year), such that incentivized LA-PrEP programs may be especially salient for younger trans adults with fewer financial resources.