Article first published online: 26 JUN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Statistics in Medicine
Special Issue: Special Issue in Honor of Jerome Cornfield on the Centennial of His Birth
Volume 31, Issue 24, pages 2844–2857, 30 October 2012
How to Cite
Wu, X. and Cui, L. (2012), Group sequential and discretized sample size re-estimation designs: a comparison of flexibility. Statist. Med., 31: 2844–2857. doi: 10.1002/sim.5395
- Issue published online: 5 OCT 2012
- Article first published online: 26 JUN 2012
- Manuscript Accepted: 13 MAR 2012
- Manuscript Received: 25 AUG 2010
- discretized re-estimation design;
- group sequential test;
- performance score;
- power and sample size
In clinical trials, researchers usually determine a study sample size prior to the start of the study to provide a sufficient power at a targeted treatment difference. When the targeted treatment difference deviates from the true one, the study may either have insufficient power or use more subjects than necessary. To address the difficulty in sample size planning, researchers have developed various flexible sample size designs and compared their performances. Some previous work suggests that re-estimation designs are inefficient and that one can improve uniformly by using standard group sequential likelihood ratio tests, although more interim analyses are involved. However, researchers need to further study the statement and the minimal number of tests needed before a standard group sequential test might outperform a re-estimation design. In this paper, we conducted simulation studies to answer these questions using various optimality criteria. Copyright © 2012 John Wiley & Sons, Ltd.