Cahn D A, Salmon D P, Monsch A U, Butters N, Wiederholt W C, Corey-Bloom J, Barrett-Connor E
Department of Neurosciences, University of California, San Diego, La Jolla, 92093-0948, USA.
Arch Clin Neuropsychol. 1996;11(6):529-39.
This study reports the sensitivity and specificity of the Clock Drawing Test (CDT) for detecting dementia of the Alzheimer type in a community-dwelling sample of elderly subjects. Forty-two patients with clinically diagnosed Alzheimer's disease and 237 cognitively intact subjects were administered the CDT as part of an epidemiological study of aging and dementia. Three individual measures of clock drawing performance (quantitative score, qualitative score, and combined quantitative and qualitative score) were determined for each participant. When qualitative elements such as errors and strategies were incorporated into the CDT score, the sensitivity was 84% and the specificity was 72%. The findings suggest that a CDT score which evaluates qualitative and quantitative features provides reasonably good discrimination between normal elderly individuals and DAT patients. However, the CDT appears to have limited utility as a single screening instrument in the community. Instruments such as the Dementia Rating Scale (Mattis, 1976) provide better discrimination of DAT, indicating that functions such as memory and verbal fluency need to be assessed during screening.
本研究报告了在社区居住的老年受试者样本中，画钟试验（CDT）检测阿尔茨海默型痴呆的敏感性和特异性。作为衰老与痴呆流行病学研究的一部分，对42例临床诊断为阿尔茨海默病的患者和237例认知功能正常的受试者进行了画钟试验。为每位参与者确定了画钟表现的三项个体测量指标（定量评分、定性评分以及定量与定性综合评分）。当将诸如错误和策略等定性因素纳入画钟试验评分时，敏感性为84%，特异性为72%。研究结果表明，评估定性和定量特征的画钟试验评分在正常老年人和阿尔茨海默病患者之间能提供较好的区分度。然而，画钟试验作为社区中的单一筛查工具，其效用似乎有限。诸如痴呆评定量表（马蒂斯，1976年）等工具对阿尔茨海默病的区分度更好，这表明在筛查过程中需要评估诸如记忆和语言流畅性等功能。
