Wong Adrian, Law Lorraine S N, Liu Wenyan, Wang Zhaolu, Lo Eugene S K, Lau Alexander, Wong Lawrence K S, Mok Vincent C T
From the Department of Medicine and Therapeutics, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, P.R. China.
From the Department of Medicine and Therapeutics, Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, P.R. China
Stroke. 2015 Dec;46(12):3547-50. doi: 10.1161/STROKEAHA.115.011226. Epub 2015 Oct 15.
The objective of this study is to examine the discrepancy between single versus age and education corrected cutoff scores in classifying performance on the Montreal Cognitive Assessment (MoCA) in patients with stroke or transient ischemic attack.
MoCA norms were collected from 794 functionally independent and stroke- and dementia-free persons aged ≥65 years. magnetic resonance imaging was used to exclude healthy controls with significant brain pathology and medial temporal lobe atrophy. Cutoff scores at 16th, 7th, and 2nd percentiles by age and education were derived for the MoCA and MoCA 5-minute Protocol. MoCA performance in 919 patients with stroke or transient ischemic attack was classified using the single and norm-derived cutoff scores.
The norms for the Hong Kong version of the MoCA total and domain scores and the total score of the MoCA 5-minute protocol are described. Only 65.1% and 25.7% healthy controls and 45.2% and 19.0% patients scored above the conventional cutoff scores of 21/22 and 25/26 on the MoCA. Using classification with norm-derived cutoff scores as reference, locally derived cutoff score of 21/22 yielded a classification discrepancy of ≤42.4%. Discrepancy increased with higher age and lower education level, with the majority being false positives by single cutoffs. With the 25/26 cutoff of the original MoCA, discrepancy further increased to ≤74.3%.
Conventional single cutoff scores are associated with substantially high rates of misclassification especially in older and less-educated patients with stroke. These results caution against the use of one-size-fits-all cutoffs on the MoCA.
本研究旨在探讨在对中风或短暂性脑缺血发作患者进行蒙特利尔认知评估（MoCA）时，单一临界值与年龄和教育程度校正后的临界值在分类表现上的差异。
从794名年龄≥65岁、功能独立且无中风和痴呆的人群中收集MoCA常模。使用磁共振成像排除有明显脑病变和内侧颞叶萎缩的健康对照。得出了MoCA及MoCA 5分钟协议按年龄和教育程度在第16、第7和第2百分位数的临界值。使用单一临界值和根据常模得出的临界值对919例中风或短暂性脑缺血发作患者的MoCA表现进行分类。
描述了香港版MoCA总分、各领域得分及MoCA 5分钟协议总分的常模。在MoCA上，只有65.1%的健康对照和25.7%的患者、45.2%的中风患者和19.0%的患者得分高于21/22和25/26的传统临界值。以根据常模得出的临界值分类作为参考，本地得出的21/22临界值产生的分类差异≤42.4%。差异随着年龄增长和教育水平降低而增加，大多数单一临界值导致的是假阳性。采用原始MoCA的25/26临界值时，差异进一步增至≤74.3%。
传统的单一临界值与相当高的错误分类率相关，尤其是在年龄较大和受教育程度较低的中风患者中。这些结果警示不要在MoCA上使用一刀切的临界值。
