Validation of a community survey methodology for measuring PMTCT impact

描述(由申请人提供)：预防母婴艾滋病毒传播(PMTCT)实施科学中的一个关键差距是缺乏有效的方法来衡量方案的有效性。虽然这一需要已被认识到多年，但随着2011年联合国艾滋病规划署、防治艾滋病紧急救援计划和其他全球合作伙伴发起“消除母婴传播”(EMTCT)运动，这一需求已成为当务之急。除了大幅扭转儿科艾滋病流行的雄心勃勃的目标之外，EMTCT还呼吁采取新的措施来定义项目的成功。项目覆盖率等传统指标已被无艾滋病毒生存等直接健康结果所取代，这是一个重要的范式转变，需要新的创新评估方法。世界卫生组织目前正在为防止母婴传播的评估制定指导方针，他们建议的方法之一是社区调查。该调查方法的优势在于其人口抽样、衡量无艾滋病毒存活率的能力、具有回溯性数据收集的横断面设计，以及易于纳入正在进行的全国性举措(例如，人口和健康调查)。然而，潜在的确定和报告偏差可能导致不准确的结果。如果建议将这一方法用于更广泛的实施，则迫切需要正式的验证。为了解决这一重要的知识鸿沟，提出了一项由两部分组成的研究。首先，社区调查方法将对照“黄金标准”社区队列设计进行验证。为支持这一目标，来自42个社区的10,500户家庭(每个社区250户)的回溯性社区调查数据将被用于计算18个月大的艾滋病毒感染儿童的无艾滋病毒存活率。与此同时，1680名感染艾滋病毒的新生儿将在同一社区的队列中登记(每个社区40名)，并预期跟踪18个月。将比较两种方法对无艾滋病毒生存的测量结果，并确定调查方法的有效性。其次，将通过收集设施级别的数据--包括对患者护理的直接观察、患者接触时间的评估和供应库存水平--并通过调查和队列方法将这些数据与社区级别的无艾滋病毒生存率相关联，从而确定与改善的预防母婴传播结果相关的计划特征和做法。通过这种方式，这项研究将确定预防母婴传播的“最佳做法”，并可能为干预研究产生新的科学问题，这是实施科学在防治艾滋病紧急救援计划框架内的一个关键职能。这项研究的结果预计将对赞比亚的防止母婴传播方案评估产生直接影响，并立即为全球监测和评估政策建议提供信息。

DESCRIPTION (provided by applicant): A key gap in prevention of mother-to-child HIV transmission (PMTCT) implementation science is the lack of validated approaches to measure program effectiveness. Although this need has been recognized for years, it has come to the forefront with the 2011 launch of the "eliminating mother-to-child HIV transmission" (EMTCT) campaign by UNAIDS, PEPFAR, and other global partners. Alongside ambitious goals to dramatically reverse the pediatric AIDS epidemic, EMTCT calls for new measures to define program success. Traditional metrics such as program coverage have been replaced with direct health outcomes such as HIV-free survival, an important paradigm shift that will require new and innovative evaluation approaches. The World Health Organization is currently developing guidelines for PMTCT evaluation and among their recommended methodologies is a community survey. Strengths of the survey approach are its population-level sampling, an ability to measure HIV-free survival, a cross-sectional design with retrospective data collection, and the ease with which it could be incorporated into ongoing nationwide initiatives (e.g., Demographic and Health Surveys). However, potential ascertainment and reporting biases could lead to inaccurate results. If this methodology is to be recommended for broader implementation, a formal validation is urgently needed. To address this important knowledge gap, a two-part study is proposed. First, a community survey methodology will be validated against a "gold standard" community cohort design. In support of this aim, retrospective community survey data from 10,500 households across 42 communities (250 per community) involved in the ongoing Better Health Outcomes through Mentorship and Assessment (BHOMA) study will be used to calculate HIV- free survival in HIV-exposed children at 18 months of age. In parallel, 1,680 HIV-exposed newborns will be enrolled in cohorts across the same communities (40 per community) and followed prospectively for 18 months. Measurements of HIV-free survival from the two methodologies will be compared, and the validity of the survey approach determined. Second, program characteristics and practices associated with improved PMTCT outcomes will be identified by collecting facility-level data-including direct observations of patient care, assessment of patient encounter times, and supply inventory levels-and correlating them with community- level HIV-free survival from both the survey and cohort methodologies. In this manner, the study will identify "best practices" for PMTCT and potentially generate new scientific questions for interventional research, a key function of implementation science within PEPFAR's framework. The results from the study are expected to have a direct impact on PMTCT program evaluation in Zambia and immediately inform monitoring and evaluation policy recommendations globally.