Abstract
INTRODUCTION: Adolescents and young adults (AYA) are disproportionately at risk of HIV acquisition. Person-centred online platforms could effectively reach AYA with HIV testing services. We assessed the effectiveness of Stand By You, a mobile application, in delivering HIV-related services to at-risk Thai AYAs. METHODS: Deidentified data from clients who accessed Stand By You services between August 2022 and February 2024 were analysed. HIV self-testing (HIVST) services were promoted through TikTok influencers to target AYAs vulnerable to HIV. An automated chatbot provided real-time responses to client inquiries, and trained counsellors provided confidential, text-based counselling daily. Clients who completed risk assessments received personalized recommendations for HIVST based on their risk profile. Clients who submitted their HIVST results received post-test counselling and linkage to care and prophylactic treatment. Multivariable logistic regression was used to assess risk factors for reactive HIVST kit results. The per unit direct cost of the programme's performance metrics were assessed. RESULTS: A total of 8863 clients provided 11,536 risk assessments. The majority were male (76.3%), under the age of 30 (76.0%), identified as members of key populations (60.4%) and first-time testers (56.1%). Additionally, 27.8% had a history of sexually transmitted infections (3,202/11,536), 16.5% reported receiving money or incentives for sex (1908/11,536) and clients indicated an average of 2.6 sexual partners in the past month (SD 3.4). Out of 7585 submitted HIVST results, 3.6% were reactive (n = 274); 60.2% were linked to care (n = 165/274) and 10.4% are in the process of linkage (n = 23/274). Of the 5.3% invalid results reported (n = 401/7585), nearly all were non-reactive by the second HIVST (117/187). A history of testing HIV negative (adjusted odds ratio [aOR] 0.54 [95% CI 0.40-0.72], p < 0.001) and receiving pre-exposure prophylaxis (aOR 0.20 [95% CI 0.06-0.64], p = 0.007) were independently associated with reduced odds of a reactive result. Average direct cost was $18.7, $40.3 and $1100 USD per distributed HIVST kit, first-time tester and new client linked to care, respectively. CONCLUSIONS: AYA populations at risk for HIV can be effectively reached through mobile phone applications that provide services anonymously. Online strategies for HIVST delivery and supportive text-based counselling can generate high demand, engagement and successful linkage to care.