An Information-Theoretic Approach for the Evaluation of Surrogate Endpoints Based on Causal Inference
An Information-Theoretic Approach for the Evaluation of Surrogate Endpoints Based on Causal Inference
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DOI:
10.1111/biom.12483
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发表时间:
2016-09-01
期刊:
影响因子:
1.9
通讯作者:
Burzykowski, Tomasz
中科院分区:
文献类型:
--
作者:
Alonso, Ariel;Van der Elst, Wim;Burzykowski, Tomasz
In this work a new metric of surrogacy, the so-called individual causal association (ICA), is introduced using information-theoretic concepts and a causal inference model for a binary surrogate and true endpoint. The ICA has a simple and appealing interpretation in terms of uncertainty reduction and, in some scenarios, it seems to provide a more coherent assessment of the validity of a surrogate than existing measures. The identifiability issues are tackled using a two-step procedure. In the first step, the region of the parametric space of the distribution of the potential outcomes, compatible with the data at hand, is geometrically characterized. Further, in a second step, a Monte Carlo approach is proposed to study the behavior of the ICA on the previous region. The method is illustrated using data from the Collaborative Initial Glaucoma Treatment Study. A newly developed and user-friendly R package Surrogate is provided to carry out the evaluation exercise.