Paper Info
Title
Sample Size Calculation for Comparing Time-Averaged Responses in K-Group Repeated-Measurement Studies.
Abstract
Many clinical trials compare the efficacy of K (≥3) treatments in repeated measurement studies. However, the design of such trials have received relatively less attention from researchers. Zhang & Ahn (2012) derived a closed-form sample size formula for two-sample comparisons of time-averaged responses using the generalized estimating equation (GEE) approach, which takes into account different correlation structures and missing data patterns. In this paper, we extend the sample size formula to scenarios where K (≥3) treatments are compared simultaneously to detect time-averaged differences in treatment effect. A closed-form sample size formula based on the noncentral χ(2) test statistic is derived. We conduct simulation studies to assess the performance of the proposed sample size formula under various correlation structures from a damped exponential family, random and monotone missing patterns, and different observation probabilities. Simulation studies show that empirical powers and type I errors are close to their nominal levels. The proposed sample size formula is illustrated using a real clinical trial example.
Year
DOI
Venue
2013
10.1016/j.csda.2012.08.013
Computational Statistics & Data Analysis
Keywords
Field
DocType
different observation probability,clinical trial,monotone missing pattern,account different correlation structure,missing data pattern,sample size formula,real clinical trial example,sample size calculation,closed-form sample size formula,proposed sample size formula,simulation study,time-averaged response,k-group repeated-measurement study,sample size
Econometrics,Test statistic,Exponential family,Correlation,Missing data,Treatment effect,Statistics,Mathematics,Sample size determination,Generalized estimating equation,Monotone polygon
Journal
Volume
ISSN
Citations 
58
0167-9473
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Song Zhang1322.34
Chul Ahn200.34