Abstract
When testing for superiority in a parallel-group setting with a continuous outcome, adjusting for covariates is usually recommended. For this purpose, the analysis of covariance is frequently used, and recently several exact and approximate sample size calculation procedures have been proposed. However, in case of multiple covariates, the planning might pose some practical challenges and pitfalls. Therefore, we propose a method, which allows for blinded re-estimation of the sample size during the course of the trial. Simulations confirm that the proposed method provides reliable results in many practically relevant situations, and applicability is illustrated by a real-life data example.
Document Type
Article
Publication Date
2020
Digital Object Identifier (DOI)
https://doi.org/10.1080/10543406.2019.1632871
Funding Information
This work was supported by the Austrian Science Fund [I 2697-N31].
Repository Citation
Zimmermann, Georg; Kieser, Meinhard; and Bathke, Arne C., "Sample Size Calculation and Blinded Recalculation for Analysis of Covariance Models with Multiple Random Covariates" (2020). Statistics Faculty Publications. 28.
https://uknowledge.uky.edu/statistics_facpub/28
Supplemental material
Notes/Citation Information
Published in Journal of Biopharmaceutical Statistics, v. 30, issue 1.
© 2019 The Author(s). Published with license by Taylor & Francis Group, LLC.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.