在具有时间-事件结局的纵向观察性研究中,因果分析的一个常见目标是在假设干预情景下估计因果生存曲线。g-formula 是进行该分析的有用工具。为增强传统参数化 g-formula,我们开发了一种替代的 g-formula 估计量,将 Bayesian Additive Regression Trees (BART) 纳入时变生成成分的建模中,旨在减轻因模型误设导致的偏倚。我们聚焦于二值时间变化治疗,并针对离散生存数据引入一类可纳入纵向平衡得分的通用 g-formula。这些纵向平衡得分的最小充分形式与治疗策略的性质(即静态或动态)相关联。针对每种治疗策略类型,我们提供了后验采样算法。我们进行了模拟以说明所提方法的经验性能,并利用 Yale New Haven Health System 电子健康记录数据展示了其实际效用。
英文摘要:
In longitudinal observational studies with time-to-event outcomes, a common objective in causal analysis is to estimate the causal survival curve under hypothetical intervention scenarios. The g-formula is a useful tool for this analysis. To enhance the traditional parametric g-formula, we developed an alternative g-formula estimator, which incorporates the Bayesian Additive Regression Trees (BART) into the modeling of the time-evolving generative components, aiming to mitigate the bias due to model misspecification. We focus on binary time-varying treatments and introduce a general class of g-formulas for discrete survival data that can incorporate the longitudinal balancing scores. The minimum sufficient formulation of these longitudinal balancing scores is linked to the nature of treatment strategies, i.e., static or dynamic. For each type of treatment strategy, we provide posterior sampling algorithms. We conducted simulations to illustrate the empirical performance of the proposed method and demonstrate its practical utility using data from the Yale New Haven Health System's electronic health records.
Bayesian Sensitivity Analysis for Causal Estimation with Time-varying Unmeasured Confounding
Dalla Lana School of Public Health, University of Toronto(多伦多大学达拉·兰纳公共卫生学院);Public Health Ontario(安大略省公共卫生局);Rutgers School of Public Health, Rutgers University(罗格斯大学罗格斯公共卫生学院);Division of Gastroenterology, Hepatology Nutrition, The Hospital for Sick Children(儿童医院胃肠病学、肝病营养科);University of Utah and Intermountain Healthcare Primary Children’s Hospital(犹他大学和山脊医疗初级儿童医院);Institute of Health Policy, Management and Evaluation, University of Toronto(多伦多大学卫生政策、管理与评估研究所)
Proximal Causal Inference for Marginal Counterfactual Survival Curves
对比治疗组间的边缘反事实生存曲线是推断干预对右删失至事件时间结局的因果影响的有效且流行的方法。在观察环境中得出此类推论的一个关键挑战是可能存在未测量的混杂,这可能使假设没有隐藏混杂偏倚的最常用方法无效。在本文中,我们没有做出标准的无不可测量混杂假设,而是扩展了Miao et al.(2018),Tchetgen et al.(2020),Cui et al.(2020)最近提出的近端因果推断框架,以通过利用观察到的协变量作为不可测量混杂因素的不完美代理来获得因果生存对比的非参数识别。具体来说,我们开发了一个近端逆概率加权(PIPW)估计,标准IPW的近端模拟,它允许观察到的数据分布的时间到事件的结果,以保持完全不受限制。PIPW估计依赖于所谓的治疗混杂桥接函数的参数模型,该桥接函数将治疗过程与混杂代理相关联。因此,PIPW可能对模型错误指定敏感。为了提高稳健性和效率,我们还提出了一个近似双稳健估计,并建立了一致相合性和渐近正态性的估计。我们进行了广泛的模拟,以检查我们的估计有限样本的性能,并提出的方法应用于一项研究,评估重症监护室的重症患者的右心导管插入术的有效性。
Using Heteroscedasticity for Causal Discovery under Hidden Confounding
School of Mathematical Sciences, Peking University(北京大学数学科学学院);Center for Applied Statistics and School of Statistics, Renmin University of China(中国人民大学应用统计科学中心及统计学院);School of Mathematical Sciences and Center for Statistical Science, Peking University(北京大学数学科学学院及统计科学中心)
Observing the unobserved confounding through its effects: toward randomized trial-like estimates from real-world survival data
Operations Research Center, Massachusetts Institute of Technology(麻省理工学院运营研究中心);Sloan School of Management, Massachusetts Institute of Technology(麻省理工学院斯隆管理学院);Department of Surgery, Memorial Sloan Kettering Cancer Center(纪念斯隆凯特琳癌症中心外科部);Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin(柏林夏里特医学院,柏林自由大学和洪堡大学联合成员)
Causal Discovery of Linear Non-Gaussian Causal Models with Unobserved Confounding
TUM School of Computation, Information and Technology(慕尼黑工业大学计算、信息与技术学院);Technical University of Munich(慕尼黑工业大学);University of British Columbia(不列颠哥伦比亚大学);Munich Center for Machine Learning(慕尼黑机器学习中心)
Doubly Robust Proximal Causal Inference under Confounded Outcome-Dependent Sampling
未测量的混杂和选择偏倚在观察性研究中经常引起关注,如果不适当解释,可能会使因果分析无效。在结果依赖性抽样下,对治疗、结果和样本选择过程具有因果影响的潜在因素可能导致不可测量的混杂和选择偏倚,从而在没有额外假设的情况下无法识别标准因果参数。在处理效应的比值比模型下,Li et al. 2022通过利用一对阴性对照变量作为混杂和选择偏倚来源的潜在因素的代理,建立了因果效应的近端识别和估计。然而,他们的方法完全依赖于所谓的治疗混淆桥函数的存在和正确规范,这是一种限制治疗分配机制的模型。在这篇文章中,我们提出了双重稳健估计的优势比模型下的两个滋扰功能-治疗混杂桥函数和结果混杂桥函数,限制了结果的法律,使我们的估计是一致的,渐近正常的,如果桥函数模型是正确的指定,而不知道哪一个是。因此,我们提出的双稳健估计量可能比Li等人的估计量更稳健。我们的模拟证实,提出的优势比因果效应的近端估计可以充分考虑剩余混杂和选择偏差,在规定的条件下,校准良好的置信区间在广泛的情况下,标准方法通常无法保持一致。此外,建议的双重稳健估计是一致的,如果至少有一个混杂桥函数被正确指定。
Discussion on "Bayesian Regression Tree Models for Causal Inference: Regularization, Confounding, and Heterogeneous Effects" by Hahn, Murray and Carvalho