Journal ArticleDOI
67A Designed extension of studies based on conditional power
Reads0
Chats0
TLDR
A flexible method of extending a study based on conditional power, where the significance of the treatment difference at the planned end is used to determine the number of additional observations needed and the critical value necessary after accruing those additional observations.About:
This article is published in Controlled Clinical Trials.The article was published on 1995-06-01. It has received 252 citations till now. The article focuses on the topics: Extension (predicate logic).read more
Citations
More filters
Journal ArticleDOI
Adaptive sample size calculations in group sequential trials.
Walter Lehmacher,Gernot Wassmer +1 more
TL;DR: A method for group sequential trials that is based on the inverse normal method for combining the results of the separate stages is proposed, which enables data-driven sample size reassessments during the course of the study.
Journal ArticleDOI
Modification of Sample Size in Group Sequential Clinical Trials
Lu Cui,H. M. J. Hung,S.-J. Wang +2 more
TL;DR: A new group sequential test procedure is developed by modifying the weights used in the traditional repeated significance two-sample mean test, which has the type I error probability preserved at the target level and can provide a substantial gain in power with the increase of sample size.
Journal ArticleDOI
Adaptive design methods in clinical trials – a review
Shein-Chung Chow,Mark Chang +1 more
TL;DR: Several commonly considered adaptive designs in clinical trials are reviewed and some examples concerning the development of Velcade intended for multiple myeloma and non-Hodgkin's lymphoma are given.
Journal ArticleDOI
Adaptive designs in clinical trials: why use them, and how to run and report them
Philip Pallmann,Alun Bedding,Babak Choodari-Oskooei,Munyaradzi Dimairo,Laura Flight,Lisa V. Hampson,Lisa V. Hampson,Jane Holmes,Adrian Mander,Lang’o Odondi,Matthew R. Sydes,Sofia S. Villar,James Wason,James Wason,Christopher J. Weir,Graham M. Wheeler,Graham M. Wheeler,Christina Yap,Thomas Jaki +18 more
TL;DR: This tutorial paper provides guidance on key aspects of adaptive designs that are relevant to clinical triallists, and emphasises the general principles of transparency and reproducibility and suggest how best to put them into practice.
Journal ArticleDOI
Adaptive Group Sequential Designs for Clinical Trials: Combining the Advantages of Adaptive and of Classical Group Sequential Approaches
Hans-Helge Müller,Helmut Schäfer +1 more
TL;DR: A general method is presented integrating the concept of adaptive interim analyses into classical group sequential testing to allow the researcher to represent every group sequential plan as an adaptive trial design and to make design changes during the course of the trial after every interim analysis.
References
More filters
Journal ArticleDOI
Efficient group sequential designs when there are several effect sizes under consideration
TL;DR: By examining the performance of optimal procedures within each class, it is concluded that class B provides simple and efficient designs with efficiency close to that of the more complex designs of classes C and D.
Journal ArticleDOI
Are flexible designs sound
Carl-Fredrik Burman,C Sonesson +1 more
TL;DR: It is concluded that flexible design in its most general form with the corresponding weighted test is not valid and several possible modifications of the flexible design methodology are discussed with a focus on alternative hypothesis tests.
Journal ArticleDOI
Sample Size Reestimation: A Review and Recommendations:
TL;DR: This article reviews commonly used approaches to adjust sample size and provides recommendations on how SSR should be implemented to achieve the objectives and maintain the integrity of the trial.
Journal ArticleDOI
Frequentist evaluation of group sequential clinical trial designs
TL;DR: This paper describes how the frequentist operating characteristics of a particular stopping rule might be evaluated to ensure that the selected clinical trial design satisfies the constraints imposed by the many different disciplines represented by the clinical trial collaborators.
Journal ArticleDOI
Adaptive seamless designs: selection and prospective testing of hypotheses.
TL;DR: Where gains are possible using the adaptive approach, a variety of logistical, operational, data handling and other practical difficulties remain to be overcome if adaptive, seamless designs are to be effectively implemented.