Socio-economic factors predicting drop-out of paediatric HIV prevention programming among adolescent mothers in South Africa

撒哈拉以南非洲的艾滋病毒感染率和意外少女怀孕率是全世界最高的；在这两个挑战中，少女和年轻妇女承担着最严重的社会经济和健康后果。在全球艾滋病毒携带者人数最多的南非，由于几个社会、关系和生物风险因素，如年龄差异的关系、交易性行为和亲密伴侣暴力，青少年女性仍占所有新感染病例的近三分之一。预防母婴传播(母婴传播)是控制艾滋病毒流行的关键，因为母婴传播给母亲、其子女和更广泛的社会造成了一些不利的健康和社会经济后果。南非青少年母亲的母婴传播率比成年人高出三倍，使她们成为预防规划干预的关键但往往被忽视的优先人群。因此，迫切需要了解南非青少年及其婴儿在哪里、何时和为什么退出预防母婴传播服务，以及在哪里可以改进这些服务，以最终消除儿童艾滋病毒感染。拟议的DPHIL研究旨在通过量化新冠肺炎发病前和发病后青少年母亲在预防母婴传播计划中的保留率来回答这些问题，并确定哪些社会经济因素预测较差的儿科艾滋病毒预防结果。为此，这项研究将利用来自南非东开普省的一大批多波青少年母亲及其子女的数据，他们参加了嘿Baby纵向研究(开普敦大学和牛津大学之间的研究合作)。这些数据在三个方面是独一无二的：i)纳入1,000多对母婴，两者都有关联数据；ii)其纵向性质，跨越新冠肺炎大流行爆发前后的三波；iii)多数据来源，包括每对母婴的自我报告访谈、患者档案和医疗实验室记录。这些丰富的数据使人们能够使用更先进的统计方法，包括边际效应模型、分类和回归树分析、人口归因率分析和通径分析结构方程模型，所有这些都将被用来确定预防母婴传播方案的哪些阶段应该改进，以及哪些可改变的社会经济因素对儿科艾滋病毒的结果有最重大的影响。这将提供基于证据的政策和规划指导，确定政府和资助者可以有效优先考虑其投资和干预努力的关键领域。

Sub-Saharan Africa has the highest rates of both HIV infection and unintended adolescent pregnancy worldwide; two challenges in which adolescent girls and young women bear the greatest socio-economic and health consequences. In South Africa, which is home to the largest population of people living with HIV globally, adolescent women still account for nearly a third of all new infections, due to several social, relational, and biological risk factors such as age-disparate relationships, transactional sex, and intimate partner violence. Critical to the control of the HIV epidemic is the prevention of mother-to-child transmission (PMTCT), as this causes several adverse health and socio-economic outcomes for mothers, their children, and society more broadly. Adolescent mothers in South Africa have up to three times higher rates of mother-to-child transmission compared to adults, making them a critical, yet often overlooked, priority population for prevention programming intervention. Thus, there exists an urgent need to understand where, when, and why South African adolescents and their babies drop out of PMTCT services, and where these services can be improved to ultimately eliminate paediatric HIV infection. The proposed DPhil research aims to answer these questions by quantifying retention in PMTCT programming among adolescent mothers pre- and post-COVID-19-onset, and determining which socio-economic factors predict poor paediatric HIV prevention outcomes. To this end, the research will draw upon data from a large, multi-wave cohort of adolescent mothers and their children living in the Eastern Cape Province, South Africa, enrolled in the HEY BABY longitudinal study (a research collaboration between the Universities of Cape Town and Oxford). This data is unique in three ways: i) the inclusion of over 1000 mother-child pairs, with linked data for both, ii) its longitudinal nature, spanning three waves pre- and post-onset of the COVID-19 pandemic, and iii) multiple data sources, including self-report interviews, patient files, and medical laboratory records for each mother-child pair. This rich data allows for the use of more advanced statistical methodology, including marginal effects modelling, classification and regression tree analysis, population attributable fraction analysis, and path analysis structural equation modelling, all of which will be employed to determine which stages of PMTCT programming should be improved, and which modifiable socio-economic factors have the most significant impact on paediatric HIV outcomes. This will provide evidence-based policy and programming guidance, identifying key areas where government and funders can effectively prioritise their investments and intervention efforts.