Journal ArticleDOI
67A Designed extension of studies based on conditional power
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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
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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.
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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
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Journal ArticleDOI
Adaptive and nonadaptive group sequential tests
TL;DR: In this paper, the authors evaluate schemes for adaptive redesign, extending the theoretical arguments for use of sufficient statistics of Tsiatis & Mehta (2003), and assess the possible benefits of preplanned adaptive designs by numerical computation of optimal tests.
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Sample size re-estimation for adaptive sequential design in clinical trials.
TL;DR: This work describes a method for sample size re-estimation at the penultimate stage of a group sequential design that achieves specified power against an alternative hypothesis corresponding to the current point estimate of the treatment effect.
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Adaptive Dunnett tests for treatment selection.
TL;DR: The adaptive procedure uniformly improves the classical Dunnett test, which is shown to be strictly conservative if treatments are dropped at interim if the specific selection rule does not need to be pre-specified in advance to control the multiple type I error rate.
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Methods for identification and confirmation of targeted subgroups in clinical trials: A systematic review
Thomas Ondra,Alex Dmitrienko,Tim Friede,Alexandra Graf,Frank Miller,Nigel Stallard,Martin Posch +6 more
TL;DR: A literature review on methodological approaches to the design and analysis of clinical trials investigating a potential heterogeneity of treatment effects across subgroups finds that exploratory and confirmatory subgroup analysis, frequentist, Bayesian and decision-theoretic approaches are identified.
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A sample size adjustment procedure for clinical trials based on conditional power
TL;DR: A procedure for calculating additional sample size needed based on conditional power, and adjusting the final-stage critical value to protect the overall type-I error rate is proposed and has better flexibility in setting up interim decision rules and thefinal-stage test is a likelihood ratio test.