Constrained S-estimators for linear mixed effects models with covariance components.
Constrained S-estimators for linear mixed effects models with covariance components.
复制标题
用于具有协方差分量的线性混合效应模型的约束 S 估计器。
DOI:
10.1002/sim.4169
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发表时间:
2011
影响因子:
2
通讯作者:
Vishnyakov,Mark
中科院分区:
文献类型:
--
作者:
Chervoneva,Inna;Vishnyakov,Mark
Linear mixed effects (LME) models are increasingly used for analyses of biological and biomedical data. When the multivariate normal assumption is not adequate for an LME model, then a robust estimation approach is preferable to the maximum likelihood one. M‐estimators were considered before for robust estimation of the LME models, and recently a constrained S‐estimator was proposed. This S‐estimator cannot be applied directly to LME models with correlated error terms and vector random effects with correlated dimensions. Therefore, a modification is proposed, which extends application of the constrained S‐estimator to the LME models for multivariate responses with correlated dimensions and to longitudinal data. Also, a new computational algorithm is developed for computing constrained S‐estimators. Performance of the S‐estimators based on the original Tukey's biweight and translated biweight is evaluated in a small simulation study with repeated multivariate responses with correlated dimensions. The proposed methodology is applied to jointly analyze repeated measures on three cholesterol components, HDL, LDL, and triglycerides. Copyright © 2011 John Wiley & Sons, Ltd.