iSAY (incentives for South African youth): Stated preferences of young people living with HIV.

High adherence to antiretroviral therapy (ART) is essential for achieving viral suppression and preventing HIV transmission. Yet adherence is suboptimal among adolescents who face unique adherence challenges. Little is known about the role of conditional economic incentives (CEIs) for increasing ART adherence in this population. During 2017-2019, we conducted a mixed-methods discrete choice experiment in Cape Town, South Africa to inform the optimal design of a CEI intervention for ART adherence among youth. In-depth interviews were conducted with n = 35 adolescents (10-19 years old) living with HIV and prescribed ART, to identify attributes of a youth-centered CEI intervention for ART adherence. A discrete choice experiment was subsequently conducted with N = 168 adolescents to elicit preferences for intervention components. A rank-ordered mixed logit model was used for main results; marginal willingness-to-accept (mWTA) was then estimated. Five attributes emerged from the qualitative research as important for a CEI-based intervention for youth ART adherence: (1) incentive amount, (2) incentive format, (3) incentive recipient, (4) delivery mode, and (5) program participants. Youth had a high probability of acceptance of any incentives program (88-100%), yet they did not have a strong preference of a quarterly over a monthly program. From a maximum incentive amount of R1920 (US$115), youth were willing to forgo up to R126 per year (US$9) if the incentive was given in cash (versus fashion vouchers); R274 (US$19.6) if it was open to both previously adherent and non-adherent youth (instead of non-adherent only); and up to R91 (US$6.5) to receive incentives at a clinic setting (instead of electronically). The use of incentives over the short term during the critical age- and developmental-transition, when adolescents begin to take sole responsibility for their medication-taking behaviors, holds great promise for habituating adherence into adulthood.