Given an (optimal) dynamic treatment rule, it may be of interest to evaluate that rule -- that is, to ask the causal question: what is the expected outcome had every subject received treatment according to that rule? In this paper, we study the performance of estimators that approximate the true value of: 1) an $a$ $priori$ known dynamic treatment rule 2) the true, unknown optimal dynamic treatment rule (ODTR); 3) an estimated ODTR, a so-called "data-adaptive parameter," whose true value depends on the sample. Using simulations of point-treatment data, we specifically investigate: 1) the impact of increasingly data-adaptive estimation of nuisance parameters and/or of the ODTR on performance; 2) the potential for improved efficiency and bias reduction through the use of semiparametric efficient estimators; and, 3) the importance of sample splitting based on CV-TMLE for accurate inference. In the simulations considered, there was very little cost and many benefits to using the cross-validated targeted maximum likelihood estimator (CV-TMLE) to estimate the value of the true and estimated ODTR; importantly, and in contrast to non cross-validated estimators, the performance of CV-TMLE was maintained even when highly data-adaptive algorithms were used to estimate both nuisance parameters and the ODTR. In addition, we apply these estimators for the value of the rule to the "Interventions" Study, an ongoing randomized controlled trial, to identify whether assigning cognitive behavioral therapy (CBT) to criminal justice-involved adults with mental illness using an ODTR significantly reduces the probability of recidivism, compared to assigning CBT in a non-individualized way.
翻译:根据(最优)动态治疗规则,评估这一规则可能有意义,也就是说,要问一个因果关系问题:预期结果是什么?在本文件中,我们研究估计者的实际价值大致如下:1) 美元为美元,已知的动态治疗规则2;真实的、未知的最佳动态治疗规则(ODTR);3 估计的DDTR,即所谓的“数据适应参数”,其真实价值取决于抽样。利用点处理数据的模拟,我们特别调查:(1) 越来越准确地估计每个对象都按照该规则得到治疗?在本文中,我们研究了估算者的实际价值的预期结果是什么?1,我们研究了估算者的实际价值大约为:1美元为1美元,1美元为美元,美元;3)基于CV-TMLE的样本分裂对于准确推断的重要性。在考虑的模拟中,使用经过交叉验证的参数估计的最大可能性估计值(CV-TRELE),我们具体地调查:(1) 越来越精确的对调值进行数据评估的影响;(2) 使用半分数有效估量的DNA数据,使用这些定量数据的对比和估算者对数值的估算值是使用。