Counterfactual inference for continuous rather than binary treatment
variables is more common in real-world causal inference tasks. While there are
already some sample reweighting methods based on Marginal Structural Model for
eliminating the confounding bias, they generally focus on removing the
treatment's linear dependence on confounders and rely on the accuracy of the
assumed parametric models, which are usually unverifiable. In this paper, we
propose a de-confounding representation learning (DRL) framework for
counterfactual outcome estimation of continuous treatment by generating the
representations of covariates disentangled with the treatment variables. The
DRL is a non-parametric model that eliminates both linear and nonlinear
dependence between treatment and covariates. Specifically, we train the
correlations between the de-confounded representations and the treatment
variables against the correlations between the covariate representations and
the treatment variables to eliminate confounding bias. Further, a
counterfactual inference network is embedded into the framework to make the
learned representations serve both de-confounding and trusted inference.
Extensive experiments on synthetic datasets show that the DRL model performs
superiorly in learning de-confounding representations and outperforms
state-of-the-art counterfactual inference models for continuous treatment
variables. In addition, we apply the DRL model to a real-world medical dataset
MIMIC and demonstrate a detailed causal relationship between red cell width
distribution and mortality.

我们提出了一种用于连续治疗的去混淆表示学习 (DRL) 框架，通过生成与治疗变量解耦的协变量表示来进行反事实结果估计。该框架是一个非参数模型，能够消除治疗与协变量之间的线性和非线性依赖关系，并在模型中嵌入了反事实推理网络以实现去混淆和可信的推理。在合成数据集上广泛实验表明，该 DRL 模型在学习去混淆表示方面表现卓越，并且胜过了针对连续治疗的最先进的反事实推理模型。此外，我们将该 DRL 模型应用于实际的医疗数据集 MIMIC，并展示了红细胞宽度分布与死亡率之间的详细因果关系。