Royall D R, Cordes J A, Polk M
Department of Psychiatry, University of Texas, Health Science Center at San Antonio, 78284-7792, USA.
J Neurol Neurosurg Psychiatry. 1998 May;64(5):588-94. doi: 10.1136/jnnp.64.5.588.
To describe a clock drawing task (CLOX) designed to elicit executive impairment and discriminate it from non-executive constructional failure.
90 elderly subjects were studied (45 elderly and well persons from the independent living apartments of a continuing care retirement community and 45 patients with probable Alzheimer's disease). The clock drawing performance of elderly patients was compared with that of 62 young adult controls.
Subjects received the CLOX, an executive test (EXIT25), and the mini mental state examination (MMSE). The CLOX is divided into an unprompted task that is sensitive to executive control (CLOX1) and a copied version that is not (CLOX2). Between rater reliability (27 subjects) was high for both subtests.
In elderly subjects, CLOX subscores correlated strongly with cognitive severity (CLOX1: r=-0.83 v the EXIT25; CLOX2: r=0.85 v the MMSE). EXIT25 and MMSE scores predicted CLOX1 scores independently of age or education (F(4,82)=50.7, p<0.001; R2=0.71). The EXIT25 accounted for 68% of CLOX1 variance. Only the MMSE significantly contributed to CLOX2 scores (F(4,72)= 57.2, p<0.001; R2=0.74). CLOX subscales discriminated between patients with Alzheimer's disease and elderly controls (83.1% of cases correctly classified; Wilkes' lambda=0.48, p<0.001), and between Alzheimer's disease subgroups with and without constructional impairment (91.9% of cases correctly classified; Wilkes' lambda=0.31, p<0.001).
The CLOX is an internally consistent measure that is easy to administer and displays good inter-rater reliability. It is strongly associated with cognitive test scores. The pattern of CLOX failures may discriminate clinical dementia subgroups.
描述一种旨在引发执行功能障碍并将其与非执行性结构功能障碍相区分的画钟任务（CLOX）。
研究了90名老年受试者（45名来自持续照料退休社区独立生活公寓的健康老年人和45名可能患有阿尔茨海默病的患者）。将老年患者的画钟表现与62名年轻成人对照组进行比较。
受试者接受CLOX、一项执行功能测试（EXIT25）和简易精神状态检查（MMSE）。CLOX分为对执行控制敏感的无提示任务（CLOX1）和不敏感的复制版本（CLOX2）。两个子测试的评分者间信度（27名受试者）都很高。
在老年受试者中，CLOX子分数与认知严重程度密切相关（CLOX1：与EXIT25的r = -0.83；CLOX2：与MMSE的r = 0.85）。EXIT25和MMSE分数独立于年龄或教育程度预测CLOX1分数（F(4,82)=50.7，p<0.001；R2 = 0.71）。EXIT25占CLOX1方差的68%。只有MMSE对CLOX2分数有显著贡献（F(4,72)= 57.2，p<0.001；R2 = 0.74）。CLOX子量表可区分阿尔茨海默病患者和老年对照组（83.1%的病例分类正确；威尔克斯'λ = 0.48，p<0.001），以及有和没有结构功能障碍的阿尔茨海默病亚组（91.9%的病例分类正确；威尔克斯'λ = 0.31，p<0.001）。
CLOX是一种内部一致性良好的测量方法，易于实施且评分者间信度高。它与认知测试分数密切相关。CLOX失败模式可能区分临床痴呆亚组。
