A General Form of Covariate Adjustment in Randomized Clinical Trials

Fuente: arXiv
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Main Authors: Bannick, Marlena S., Shao, Jun, Liu, Jingyi, Du, Yu, Yi, Yanyao, Ye, Ting
Format: Preprint
Published: 2023
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author Bannick, Marlena S.
Shao, Jun
Liu, Jingyi
Du, Yu
Yi, Yanyao
Ye, Ting
author_facet Bannick, Marlena S.
Shao, Jun
Liu, Jingyi
Du, Yu
Yi, Yanyao
Ye, Ting
contents In randomized clinical trials, adjusting for baseline covariates can improve credibility and efficiency for demonstrating and quantifying treatment effects. This article studies the augmented inverse propensity weighted (AIPW) estimator, which is a general form of covariate adjustment that uses linear, generalized linear, and non-parametric or machine learning models for the conditional mean of the response given covariates. Under covariate-adaptive randomization, we establish general theorems that show a complete picture of the asymptotic normality, {efficiency gain, and applicability of AIPW estimators}. In particular, we provide for the first time a rigorous theoretical justification of using machine learning methods with cross-fitting for dependent data under covariate-adaptive randomization. Based on the general theorems, we offer insights on the conditions for guaranteed efficiency gain and universal applicability {under different randomization schemes}, which also motivate a joint calibration strategy using some constructed covariates after applying AIPW. Our methods are implemented in the R package RobinCar.
format Preprint
id arxiv_https___arxiv_org_abs_2306_10213
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A General Form of Covariate Adjustment in Randomized Clinical Trials
Bannick, Marlena S.
Shao, Jun
Liu, Jingyi
Du, Yu
Yi, Yanyao
Ye, Ting
Methodology
In randomized clinical trials, adjusting for baseline covariates can improve credibility and efficiency for demonstrating and quantifying treatment effects. This article studies the augmented inverse propensity weighted (AIPW) estimator, which is a general form of covariate adjustment that uses linear, generalized linear, and non-parametric or machine learning models for the conditional mean of the response given covariates. Under covariate-adaptive randomization, we establish general theorems that show a complete picture of the asymptotic normality, {efficiency gain, and applicability of AIPW estimators}. In particular, we provide for the first time a rigorous theoretical justification of using machine learning methods with cross-fitting for dependent data under covariate-adaptive randomization. Based on the general theorems, we offer insights on the conditions for guaranteed efficiency gain and universal applicability {under different randomization schemes}, which also motivate a joint calibration strategy using some constructed covariates after applying AIPW. Our methods are implemented in the R package RobinCar.
title A General Form of Covariate Adjustment in Randomized Clinical Trials
topic Methodology
url https://arxiv.org/abs/2306.10213