Xiong Chengjie, Miller J Philip, Morris John C
Division of Biostatistics, Washington University in St Louis, St Louis, MO 63110, USA.
J Alzheimers Dis. 2003 Oct;5(5):409-18. doi: 10.3233/jad-2003-5508.
This paper studies the correlation of cognitive progression for subjects whose dementia has made a transition from a milder stage of severity to the next stage of impairment. We model the progression of cognitive decline at adjacent stages of dementia by using a general linear mixed model. We also propose a three-step procedure to detect the best configuration of the covariance matrices for the random components in the model. After the best configuration of covariance matrices for the random components in the model is determined, we then recommend another two-step process to test whether there exists a significant correlation between the rate of cognitive decline before the transition, the cognitive status at the transition time, and the rate of cognitive decline after the transition. In addition, we present asymptotic confidence interval estimates for the correlations associated with a transition. This method is applied to several composite psychometric factor scores in the longitudinal database from the Alzheimer's Disease Research Center (ADRC) at Washington University in St. Louis.
本文研究了痴呆症患者认知进展的相关性，这些患者的痴呆症已从较轻的严重程度阶段转变为下一个损伤阶段。我们使用一般线性混合模型对痴呆症相邻阶段的认知衰退进展进行建模。我们还提出了一个三步程序来检测模型中随机成分协方差矩阵的最佳配置。在确定模型中随机成分协方差矩阵的最佳配置后，我们接着推荐另一个两步过程来检验在转变前的认知衰退率、转变时的认知状态以及转变后的认知衰退率之间是否存在显著相关性。此外，我们给出了与转变相关的相关性的渐近置信区间估计。该方法应用于圣路易斯华盛顿大学阿尔茨海默病研究中心（ADRC）纵向数据库中的几个综合心理测量因子得分。
