Attribute preferences for long-acting Pre-exposure Prophylaxis (PrEP) Results of a discrete choice experiment with South African youth
Meeting Abstract OA05.05
Background: End-user input on early stage design of new HIV prevention approaches is critical to yielding products that overcome adherence challenges and ultimately achieve high uptake and use. In iPrevent, a novel, multi-phased study designed to engage youth to inform the product pipeline, we examined preferences among key attributes of long-acting PrEP. Methods: We conducted a discrete choice experiment (DCE) with 608 sexually active, PrEP-naïve male and female youth aged 18-24 residing in two townships in Cape Town, South Africa, recruited through population-based sampling of residential plots. With an experimental design, participants chose between two hypothetical products in 9 choice questions, each composed of 5 attributes. Attributes included: form (injection, implant); dosing frequency (2, 6 or 12 months); where to obtain (clinic, pharmacy, community distribution, mobile clinic); pain involved with injection or insertion; and delivery location (arm, buttock, thigh). We used a randomparameters logit model to estimate preference weights and relative importance scores (based on coefficient value ranges) for each attribute. Results: Median age was 21 (IQR: 19-22) and, by design, 66% were female. Nearly all were heterosexual (99%), had tested for HIV (95%) and were HIV negative (91% of testers). Duration between doses was the most important attribute (relative importance [RI]=2.0, 95% CI: 1.7, 2.3), with strong preference for less frequent dosing. The second most important attribute was product form (RI=0.8, 95% CI: 0.6, 0.9): injection was favored over implant. Participants also preferred delivery of a dose to the arm and disliked the thigh, and preferred mild over moderate pain. They disliked pharmacy distribution and exhibited no preference among other distribution locations. Conclusions: Youth indicated strong preferences for longer duration products and injections. Nonetheless, each attribute influenced preferences, offering nuanced insight into trade-offs that inform long-acting PrEP development.
Minnis, A., Atujuna, M., Browne, E., Ndwayana, S., Hartmann, M., Sindelo, S., ... Montgomery, E. (2018). Attribute preferences for long-acting Pre-exposure Prophylaxis (PrEP): Results of a discrete choice experiment with South African youth. AIDS Research and Human Retroviruses, 34(S1), 27. https://doi.org/10.1089/aid.2018.5000.abstracts