Shankle William R, Mangrola Tushar, Chan Timothy, Hara Junko
Medical Care Corporation, Irvine, CA, USA.
Alzheimers Dement. 2009 Jul;5(4):295-306. doi: 10.1016/j.jalz.2008.11.001.
The Memory Performance Index (MPI) quantifies the pattern of recalled and nonrecalled words of the Consortium to Establish a Registry for Alzheimer's Disease Wordlist (CWL) onto a 0 to 100 scale and distinguishes normal from mild cognitive impairment with 96% to 97% accuracy.
In group A, 121,481 independently living individuals, 18 to 106 years old, were assessed with the CWL and classified as cognitively impaired (N = 5,971) or normal (N = 115,510). The MPI and CWL immediate free recall (IFR), delayed free recall (DFR), and total free recall (TFR) scores (the outcome measures) were each regressed against predictors of age, gender, race, education, test administration method (in-person or telephone), and wordlist used. Predictor effect sizes (Cohen's f(2)) were computed for each outcome. In addition, CWL plus Functional Assessment Staging Tests (FAST) were administered to 441 normal to moderately severely demented (FAST stages 1 to 6) patients (group B). Median MPI scores were tested for significant differences across FAST stage.
For group A, the variance explained by all predictors combined was MPI = 55.0%, IFR = 24.9%, DFR = 23.4%, and TFR = 26.9%. The age effect size on MPI score was large, but it was small on IFR, DFR, and TFR. The other predictors all had negligible (<0.02) or small effect sizes (0.02 to 0.15). For group B, median MPI scores progressively declined across all FAST stages (P < .0002).
MPI score progressively declines with increasing dementia severity. Also, MPI score explains 2 to 3 times more variance than total scores, which improves ability to detect treatment effects.
记忆表现指数（MPI）将阿尔茨海默病词汇表（CWL）中回忆出的和未回忆出的单词模式量化为0至100的评分范围，并以96%至97%的准确率区分正常与轻度认知障碍。
在A组中，对121481名年龄在18至106岁之间的独立生活个体进行了CWL评估，并将其分类为认知障碍（N = 5971）或正常（N = 115510）。将MPI以及CWL即时自由回忆（IFR）、延迟自由回忆（DFR）和总自由回忆（TFR）评分（结果指标）分别与年龄、性别、种族、教育程度、测试实施方式（面对面或电话）以及使用的词汇表等预测因素进行回归分析。计算每个结果的预测效应量（科恩f(2)）。此外，对441名正常至中度重度痴呆（功能评估分期测试[FAST] 1至6期）患者进行了CWL加FAST测试（B组）。对各FAST分期的MPI中位数评分进行显著差异检验。
对于A组，所有预测因素综合解释的方差为：MPI = 55.0%，IFR = 24.9%，DFR = 23.4%，TFR = 26.9%。年龄对MPI评分的效应量较大，但对IFR、DFR和TFR的效应量较小。其他预测因素的效应量均可忽略不计（<0.02）或较小（0.02至0.15）。对于B组，所有FAST分期的MPI中位数评分均逐渐下降（P <.0002）。
MPI评分随痴呆严重程度的增加而逐渐下降。此外，MPI评分解释的方差比总分多2至3倍，这提高了检测治疗效果的能力。
