Journal
JOURNAL OF BIOPHARMACEUTICAL STATISTICS
Volume 22, Issue 3, Pages 544-564Publisher
TAYLOR & FRANCIS INC
DOI: 10.1080/10543406.2011.557792
Keywords
Empirical covariance estimator; GEE; Linear mixed models; REML
Categories
Funding
- Direct For Mathematical & Physical Scien
- Division Of Mathematical Sciences [1209014] Funding Source: National Science Foundation
Ask authors/readers for more resources
Although asymptotically, the empirical covariance estimator is consistent and robust with respect to the selection of the working correlation matrix, when the sample size is small, its bias may not be negligible. This article proposes a small sample correction for the empirical covariance estimator in general Gaussian linear models. Inference for the fixed effects based on the corrected covariance matrix is also derived. A two-way analysis of variance (ANOVA) model with repeated measures, which evaluates the effectiveness of a CB1 receptor antagonist, and a four-period crossover design, which assesses the treatment effect in subjects with intermittent claudication, serve as examples to illustrate the proposed and other investigated methods. Simulation studies show that the proposed method generally performs better than other bias-correction methods, including Mancl and DeRouen (2001), Kauermann and Carroll (2001), and Fay and Graubard (2001), in the investigated balanced designs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available