Abstract
INTRODUCTION: Adolescents and young adults (AYAs) represent a significant proportion of the global population, yet they face persistent barriers to accessing HIV services. In Sub-Saharan Africa, nearly 90% of AYA HIV cases occur within the region, with young women disproportionately affected. In Chad, while the overall HIV prevalence has declined, the risk remains high among AYA, accounting for 26.3% of all new infections. Stigma, lack of confidentiality, negative provider attitudes and structural barriers continue to hinder service utilisation, underscoring the urgent need for evidence-based, AYA-centred interventions. However, little is known about which attributes of HIV services AYA prioritise when accessing HIV care. This study applies a discrete choice experiment in Chad to systematically quantify AYA preferences for HIV services to inform the design of youth-responsive interventions. METHODS AND DATA ANALYSIS: The study employs a D-efficient fractional factorial design, developed through extensive qualitative research and pilot testing. The final design comprises 80 choice scenarios, divided into 10 blocks to reduce participant burden. The study will recruit 1000 AYA living with HIV aged 15-24 years across eight provinces, ensuring geographical and epidemiological representativeness. Participants will be randomly assigned to one of the blocks and complete eight choice tasks. Choice data will be analysed using conditional logit, mixed logit and latent class models to estimate trade-offs and preference heterogeneity. ETHICS AND DISSEMINATION: Ethical approval was obtained from the National Committee on Bioethics of Chad (#010/MESRS/SE/SG/2024). In addition to disseminating findings through scientific publications, policy briefs and stakeholder engagements, the study will incorporate a codesign process with AYA, healthcare providers and policymakers to translate research findings into actionable interventions that align with AYA preferences and improve HIV service delivery.