JSM 2012 Home

JSM 2012 Online Program

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

Online Program Home

Abstract Details

Activity Number: 36
Type: Contributed
Date/Time: Sunday, July 29, 2012 : 2:00 PM to 3:50 PM
Sponsor: Biopharmaceutical Section
Abstract - #305141
Title: Fractional Two-Step Adaptive Randomization Procedure for Delayed Response in Clinical Trials
Author(s): Jiajing Xu*+
Companies: The University of Hong Kong
Address: Room 515, Meng Wah Complex,, Hong Kong, , Hong Kong
Keywords: Response-adaptive Randomization ; Delayed Response ; Likelihood Ratio Test ; Kaplan-Meier estimator

In clinical trials, despite the widespread use of equal randomization in practice,response-adaptive randomization has attracted considerable interest. There is typically a prerun of equal randomization before the implementation of response-adaptive randomization, while it is not clear how many subjects are needed in this equal randomization prephase. We propose a two-step procedure to achieve a balance between power and response. The new design is equipped with a likelihood ratio test before skewing the allocation probability. In addition, real-time response-adaptive randomization often requires patient response to be immediately available after the treatment, while clinical response, such as tumor shrinkage, may take a period of time to exhibit. We develop both a parametric optimal allocation scheme and a nonparametric fractional model to tackle the common problem caused by delayed response in response-adaptive randomization. We evaluate the operating characteristics of the two-stage design through extensive simulation studies. The numerical results show that the proposed method satisfactorily resolves the issues involved in response-adaptive randomization and delayed response.

The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2012 program

2012 JSM Online Program Home

For information, contact jsm@amstat.org or phone (888) 231-3473.

If you have questions about the Continuing Education program, please contact the Education Department.