Brown Elizabeth R, Chen Ying Qing
Department of Biostatistics, University of Washington, Seattle, WA 98195, USA.
Stat Commun Infect Dis. 2010 Dec 21;2(1). doi: 10.2202/1948-4690.1018.
The timing of mother-to-child transmission (MTCT) of HIV is critical in understanding the dynamics of MTCT. It has a great implication to developing any effective treatment or prevention strategies for such transmissions. In this paper, we develop an imputation method to analyze the censored MTCT timing in presence of auxiliary information. Specifically, we first propose a statistical model based on the hazard functions of the MTCT timing to reflect three MTCT modes: in utero, during delivery and via breastfeeding, with different shapes of the baseline hazard that vary between infants. This model also allows that the majority of infants may be immuned from the MTCT of HIV. Then, the model is fitted by MCMC to explore marginal inferences via multiple imputation. Moreover, we propose a simple and straightforward approach to take into account the imperfect sensitivity in imputation step, and study appropriate censoring techniques to account for weaning. Our method is assessed by simulations, and applied to a large trial designed to assess the use of antibiotics in preventing MTCT of HIV.
母婴传播（MTCT）艾滋病毒的时间对于理解母婴传播动态至关重要。这对于制定任何针对此类传播的有效治疗或预防策略都具有重大意义。在本文中，我们开发了一种插补方法，用于在存在辅助信息的情况下分析截尾的母婴传播时间。具体而言，我们首先基于母婴传播时间的风险函数提出一个统计模型，以反映三种母婴传播模式：宫内传播、分娩期间传播和母乳喂养传播，不同婴儿的基线风险形状各异。该模型还允许大多数婴儿可能免受艾滋病毒母婴传播。然后，通过马尔可夫链蒙特卡罗（MCMC）对模型进行拟合，以通过多次插补探索边际推断。此外，我们提出一种简单直接的方法来考虑插补步骤中不完善的敏感性，并研究适当的删失技术以考虑断奶情况。我们的方法通过模拟进行评估，并应用于一项旨在评估抗生素在预防艾滋病毒母婴传播中使用情况的大型试验。
