Paper Info
Title
Comparison of Operating Characteristics of Commonly Used Sample Size Re-Estimation Procedures in a Two-Stage Design.
Abstract
In group sequential clinical trials, there are several sample size re-estimation methods proposed in the literature that allow for change of sample size at the interim analysis. Most of these methods are based on either the conditional error function or the interim effect size. Our simulation studies compared the operating characteristics of three commonly used sample size re-estimation methods, Chen et al. (2004), Cui et al. (1999), and Muller and Schafer (2001). Gao et al. (2008) extended the CDL method and provided an analytical expression of lower and upper threshold of conditional power where the type I error is preserved. Recently, Mehta and Pocock (2010) extensively discussed that the real benefit of the adaptive approach is to invest the sample size resources in stages and increasing the sample size only if the interim results are in the so called promising zone which they define in their article. We incorporated this concept in our simulations while comparing the three methods. To test the robustness of these methods, we explored the impact of incorrect variance assumption on the operating characteristics. We found that the operating characteristics of the three methods are very comparable. In addition, the concept of promising zone, as suggested by MP, gives the desired power and smaller average sample size, and thus increases the efficiency of the trial design.
Year
DOI
Venue
2013
10.1080/03610918.2012.661501
COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION
Keywords
DocType
Volume
Conditional power,Interim analysis,Sample size re-estimation (SSR),Two-stage designs
Journal
42
Issue
ISSN
Citations 
5
0361-0918
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Sandeep Menon121.07
Joseph Massaro200.34
Michael J. Pencina3244.43
Jerry Lewis4995.49
Yong Cheng Wang510.70