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Related papers: Asymptotic Properties of Covariate-Adjusted Adapti…

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We investigate how to improve efficiency using regression adjustments with covariates in covariate-adaptive randomizations (CARs) with imperfect subject compliance. Our regression-adjusted estimators, which are based on the doubly robust…

Econometrics · Economics 2023-06-19 Liang Jiang , Oliver B. Linton , Haihan Tang , Yichong Zhang

Traditional methods for covariate adjustment of treatment means in designed experiments are inherently conditional on the observed covariate values. In order to develop a coherent general methodology for analysis of covariance, we propose a…

Methodology · Statistics 2010-01-19 James G. Booth , Walter T. Federer , Martin T. Wells , Russell D. Wolfinger

In clinical trials, there is potential to improve precision and reduce the required sample size by appropriately adjusting for baseline variables in the statistical analysis. This is called covariate adjustment. Despite recommendations by…

Methodology · Statistics 2022-06-20 Kelly Van Lancker , Joshua Betz , Michael Rosenblum

Case-cohort design, an outcome-dependent sampling design for censored survival data, is increasingly used in biomedical research. The development of asymptotic theory for a case-cohort design in the current literature primarily relies on…

Statistics Theory · Mathematics 2012-04-13 Bin Nan , Jon A. Wellner

The present paper deals with the problem of allocating patients to two competing treatments in the presence of covariates or prognostic factors in order to achieve a good trade-off among ethical concerns, inferential precision and…

Methodology · Statistics 2012-08-17 Alessandro Baldi Antognini , Maroussa Zagoraiou

Response-adaptive randomisation (RAR) can considerably improve the chances of a successful treatment outcome for patients in a clinical trial by skewing the allocation probability towards better performing treatments as data accumulates.…

Applications · Statistics 2017-03-14 Sofia S. Villar , Jack Bowden , James Wason

Response-Adaptive Randomization (RAR) is part of a wider class of data-dependent sampling algorithms, for which clinical trials are typically used as a motivating application. In that context, patient allocation to treatments is determined…

Methodology · Statistics 2022-06-09 David S. Robertson , Kim May Lee , Boryana C. Lopez-Kolkovska , Sofia S. Villar

This paper studies inference in two-stage randomized experiments under covariate-adaptive randomization. In the initial stage of this experimental design, clusters (e.g., households, schools, or graph partitions) are stratified and randomly…

Econometrics · Economics 2026-01-16 Jizhou Liu

Although response-adaptive randomisation (RAR) has gained substantial attention in the literature, it still has limited use in clinical trials. Amongst other reasons, the implementation of RAR in real world trials raises important practical…

Applications · Statistics 2025-09-16 Rajenki Das , Nina Deliu , Mark Toshner , Sofía S Villar

In randomized clinical trials, adjustments for baseline covariates at both design and analysis stages are highly encouraged by regulatory agencies. A recent trend is to use a model-assisted approach for covariate adjustment to gain…

Methodology · Statistics 2021-07-14 Ting Ye , Jun Shao , Yanyao Yi , Qingyuan Zhao

Adaptive designs for clinical trials permit alterations to a study in response to accumulating data in order to make trials more flexible, ethical and efficient. These benefits are achieved while preserving the integrity and validity of the…

Our paper discovers a new trade-off of using regression adjustments (RAs) in causal inference under covariate-adaptive randomizations (CARs). On one hand, RAs can improve the efficiency of causal estimators by incorporating information from…

Econometrics · Economics 2025-02-19 Liang Jiang , Liyao Li , Ke Miao , Yichong Zhang

This paper illustrates asymptotic properties for a response-adaptive design generated by a two-color, randomly reinforced urn model. The design considered is optimal in the sense that it assigns patients to the best treatment, with…

Statistics Theory · Mathematics 2009-04-03 Caterina May , Nancy Flournoy

Treatment-covariate interaction tests are commonly applied by researchers to examine whether the treatment effect varies across patient subgroups defined by baseline characteristics. The objective of this study is to explore…

Methodology · Statistics 2024-03-12 Likun Zhang , Wei Ma

Response-adaptive randomization has recently attracted a lot of attention in the literature. In this paper, we propose a new and simple family of response-adaptive randomization procedures that attain the Cramer--Rao lower bounds on the…

Statistics Theory · Mathematics 2009-08-25 Feifang Hu , Li-Xin Zhang , Xuming He

We study regression discontinuity designs with the use of additional covariates for estimation of the average treatment effect. We provide a detailed proof of asymptotic normality of the covariate-adjusted estimator under minimal…

Statistics Theory · Mathematics 2023-10-16 Patrick Kramer , Alexander Kreiß

Various adaptive randomization procedures (adaptive designs) have been proposed to clinical trials. This paper discusses several broad families of procedures, such as the play-the-winner rule and Markov chain model, randomized…

Statistics Theory · Mathematics 2009-08-30 Li-Xin Zhang

It is common to conduct causal inference in matched observational studies by proceeding as though treatment assignments within matched sets are assigned uniformly at random and using this distribution as the basis for inference. This…

Methodology · Statistics 2023-11-14 Samuel D. Pimentel , Yaxuan Huang

This paper studies inference in a randomized controlled trial (RCT) with covariate-adaptive randomization (CAR) and imperfect compliance of a binary treatment. In this context, we study inference on the LATE. As in Bugni et al. (2018,2019),…

Econometrics · Economics 2023-07-25 Federico A. Bugni , Mengsi Gao

Covariate-adaptive randomization schemes such as the minimization and stratified permuted blocks are often applied in clinical trials to balance treatment assignments across prognostic factors. The existing theoretical developments on…

Methodology · Statistics 2020-07-21 Ting Ye , Yanyao Yi , Jun Shao