Blinded sample size recalculation for clinical trials with normal data and baseline adjusted analysis
Friede, Tim and Kieser, Meinhard. (2011) Blinded sample size recalculation for clinical trials with normal data and baseline adjusted analysis. Pharmaceutical Statistics, Vol.10 (No.1). pp. 8-13. ISSN 1539-1604Full text not available from this repository.
Official URL: http://dx.doi.org/10.1002/pst.398
Baseline adjusted analyses are commonly encountered in practice, and regulatory guidelines endorse this practice. Sample size calculations for this kind of analyses require knowledge of the magnitude of nuisance parameters that are usually not given when the results of clinical trials are reported in the literature. It is therefore quite natural to start with a preliminary calculated sample size based on the sparse information available in the planning phase and to re-estimate the value of the nuisance parameters (and with it the sample size) when a portion of the planned number of patients have completed the study. We investigate the characteristics of this internal pilot study design when an analysis of covariance with normally distributed outcome and one random covariate is applied. For this purpose we first assess the accuracy of four approximate sample size formulae within the fixed sample size design. Then the performance of the recalculation procedure with respect to its actual Type I error rate and power characteristics is examined. The results of simulation studies show that this approach has favorable properties with respect to the Type I error rate and power. Together with its simplicity, these features should make it attractive for practical application. (C) Copyright 2009 John Wiley & Sons, Ltd.
|Item Type:||Journal Article|
|Subjects:||R Medicine > R Medicine (General)|
|Divisions:||Faculty of Medicine > Warwick Medical School|
|Journal or Publication Title:||Pharmaceutical Statistics|
|Publisher:||John Wiley & Sons Ltd.|
|Page Range:||pp. 8-13|
|Access rights to Published version:||Restricted or Subscription Access|
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