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Journal ArticleDOI

67A Designed extension of studies based on conditional power

Michael A. Proschan, +1 more
- 01 Jun 1995 - 
- Vol. 16, Iss: 3
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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.
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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).

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Citations
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Journal ArticleDOI

Repeated confidence intervals for adaptive group sequential trials

TL;DR: It is shown how the principle of preserving the null conditional rejection probability of the remainder of the trial at the time of each adaptive change may be extended to construct one-sided confidence intervals by applying the idea to a sequence of dual tests derived from the repeated confidence intervals (RCIs) proposed by Jennison and Turnbull.
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Review of Draft FDA Adaptive Design Guidance

TL;DR: While scarce resources and ethical imperatives motivate serious consideration of adaptive designs, researchers should be fully aware of the advantages and disadvantages ofadaptive designs and adopt them cautiously.
Journal ArticleDOI

Optimal conditional error functions for the control of conditional power.

TL;DR: Two-stage designs with control of overall and conditional power are constructed that minimize the expected sample size, either for a simple point alternative or for a random mixture of alternatives given by a prior density for the efficacy parameter.
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Interim Design Modifications in Time-to-Event Studies

TL;DR: The proposed flexible method for interim design modifications in time-to-event studies is an extension of the so-called conditional rejection probability (CRP) principle, based on the conditional distribution of the test statistic given the final value of the same test statistic from a subsample, namely the learning sample.
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Adaptive clinical trial designs in oncology.

TL;DR: This article discusses practical issues from the perspective of using adaptive designs in oncology trials and investigates several aspects of the designs, including the dose-finding scheme, interim analysis, adaptive randomization, biomarker-guidedrandomization, and seamless designs.
References
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Journal ArticleDOI

Modification of Sample Size in Group Sequential Clinical Trials

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.
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Adaptive design methods in clinical trials – a review

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.
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Adaptive Designs in Clinical Drug Development—An Executive Summary of the PhRMA Working Group

TL;DR: Three particular areas where it is felt that adaptive designs can be utilized beneficially are discussed: dose finding, seamless Phase II/III trials designs, and sample size reestimation.
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Adaptive increase in sample size when interim results are promising: a practical guide with examples.

TL;DR: The benefits and limitations of adaptive sample size re-estimation for phase 3 confirmatory clinical trials are discussed and those promising circumstances in which a conventional final inference can be performed while preserving the overall type-1 error are defined.