Brain and Cognitive Sciences and Center for Visual Science, University of Rochester, Rochester, NY 14627–0270, USA.
J Clin Exp Neuropsychol. 2011 Feb;33(2):187-99. doi: 10.1080/13803395.2010.499356. Epub 2010 Aug 13.
Behavioral markers measured through neuropsychological testing in mild cognitive impairment (MCI) were analyzed and combined in multivariate ways to predict conversion to Alzheimer's disease (AD) in a longitudinal study of 43 MCI patients. The test measures taken at a baseline evaluation were first reduced to underlying components (principal component analysis, PCA), and then the component scores were used in discriminant analysis to classify MCI individuals as likely to convert or not. When empirically weighted and combined, episodic memory, speeded executive functioning, recognition memory (false and true positives), visuospatial memory processing speed, and visuospatial episodic memory were together strong predictors of conversion to AD. These multivariate combinations of the test measures achieved through the PCA were good, statistically significant predictors of MCI conversion to AD (84% accuracy, 86% sensitivity, and 83% specificity). Importantly, the posterior probabilities of group membership that accompanied the binary prediction for each participant indicated the confidence of the prediction. Most of the participants (81%) were in the highly confident probability bins (.70-1.00), where the obtained prediction accuracy was more than 90%. The strength and reliability of this multivariate prediction method were tested by cross-validation and randomized resampling.
通过对轻度认知障碍 (MCI) 患者的神经心理学测试进行行为标记分析，并以多元方式进行组合，对 43 名 MCI 患者进行的纵向研究预测其向阿尔茨海默病 (AD) 的转化。在基线评估中进行的测试首先被简化为潜在成分（主成分分析，PCA），然后使用成分得分进行判别分析，将 MCI 个体分类为可能转化或不转化。当经验加权并组合时，情景记忆、执行功能速度、识别记忆（假阳性和真阳性）、视空间记忆处理速度和视空间情景记忆是 AD 转化的强有力预测因子。通过 PCA 实现的这些测试指标的多元组合是 MCI 向 AD 转化的良好、统计学上显著的预测因子（准确率为 84%，敏感度为 86%，特异性为 83%）。重要的是，伴随每个参与者二元预测的组群成员后验概率表明了预测的置信度。大多数参与者（81%）处于高置信概率区间（.70-1.00），其中获得的预测准确率超过 90%。通过交叉验证和随机重采样测试了这种多元预测方法的强度和可靠性。
