论文标题
获得生存函数以估计时间依赖性处理的效果的匹配方法
Matching methods for obtaining survival functions to estimate the effect of a time-dependent treatment
论文作者
论文摘要
在具有二元时间依赖性处理的生存时间的观察性研究中，危险比（瞬时度量）通常用于表示治疗效果。但是，研究人员通常对生存功能的差异更感兴趣。我们提出了半参数方法，以估计治疗在生存概率方面的因果关系。目的是将治疗后的生存与在没有治疗的情况下观察到的生存功能进行比较。对于每个患者，我们根据治疗前的死亡危害（基于治疗危险）计算预后评分（基于治疗前的死亡危害）。然后，将每个治疗的患者与具有相似预后和/或倾向分数的活着，未经审查且尚未治疗的患者匹配。每个经过治疗和匹配的患者的经验都使用一个反相反概率的变体加权加权，以考虑审查的影响。我们提出了通过加权尼尔森·艾伦（Nelson-Aalen）估计器计算得出的治疗特异性生存功能（及其差异）的估计量。提出了封闭形式的方差估计器，考虑到跨匹配集的受试者的潜在复制。通过模拟评估所提出的方法，然后使用国家器官衰竭注册中心数据估计肾移植对末期肾脏疾病患者生存的影响。
In observational studies of survival time featuring a binary time-dependent treatment, the hazard ratio (an instantaneous measure) is often used to represent the treatment effect. However, investigators are often more interested in the difference in survival functions. We propose semiparametric methods to estimate the causal effect of treatment among the treated with respect to survival probability. The objective is to compare post-treatment survival with the survival function that would have been observed in the absence of treatment. For each patient, we compute a prognostic score (based on the pre-treatment death hazard) and a propensity score (based on the treatment hazard). Each treated patient is then matched with an alive, uncensored and not-yet-treated patient with similar prognostic and/or propensity scores. The experience of each treated and matched patient is weighted using a variant of Inverse Probability of Censoring Weighting to account for the impact of censoring. We propose estimators of the treatment-specific survival functions (and their difference), computed through weighted Nelson-Aalen estimators. Closed-form variance estimators are proposed which take into consideration the potential replication of subjects across matched sets. The proposed methods are evaluated through simulation, then applied to estimate the effect of kidney transplantation on survival among end-stage renal disease patients using data from a national organ failure registry.
