Ainslie N K, Murden R A
University of Kansas Medical Center, Kansas City.
J Am Geriatr Soc. 1993 Mar;41(3):249-52. doi: 10.1111/j.1532-5415.1993.tb06701.x.
To examine the effect of education on clock-drawing ability in non-demented elderly persons.
DESIGN, SETTING, PARTICIPANTS: Descriptive study of 187 elderly persons, 77 demented, 110 non-demented, 54 with 9+ years of education, 133 with 8 or fewer years of education, from three university medical center geriatric divisions.
Subjects took the Folstein Mini-Mental State Exam and were asked to draw a clock showing a time of 3 o'clock. Clocks were scored using three previously described scoring scales (Shulman, Sunderland, and Wolf-Klein). Mean scores and proportions of normal and abnormal clocks were compared for well and poorly educated non-demented subjects. Sensitivities and specificities for detecting dementia were calculated.
Mean scores of the well educated non-demented subjects were significantly better than mean scores of the poorly educated non-demented subjects on all three scales. However, proportions of abnormal clocks were not significantly different between well and poorly educated on the Wolf-Klein scale. For the poorly educated subgroup, sensitivity and specificity for detecting dementia by clock drawing were 90% and 42% by the Shulman scale, 74% and 44% by the Sunderland scale, and 48% and 90% by the Wolf-Klein scale.
Clock-drawing ability is affected by education in non-demented elderly persons. The scoring method of Wolf-Klein is least educationally affected and maximizes specificity for detecting dementia but has low sensitivity. Educational effects make clock drawing a poor single screening test for dementia in a poorly educated population.
研究教育程度对非痴呆老年人画钟能力的影响。
设计、地点、参与者：对来自三家大学医学中心老年科的187名老年人进行描述性研究，其中77名痴呆患者，110名非痴呆患者；54名受教育年限达9年及以上，133名受教育年限为8年及以下。
受试者接受福尔斯坦简易精神状态检查表测试，并被要求画一个显示3点的时钟。使用之前描述的三种评分量表（舒尔曼量表、桑德兰量表和沃尔夫 - 克莱因量表）对时钟进行评分。比较受教育程度高和低的非痴呆受试者的平均得分以及正常和异常时钟的比例。计算检测痴呆的敏感性和特异性。
在所有三种量表上，受教育程度高的非痴呆受试者的平均得分显著高于受教育程度低的非痴呆受试者。然而，在沃尔夫 - 克莱因量表上，受教育程度高和低的受试者中异常时钟的比例没有显著差异。对于受教育程度低的亚组，通过画钟检测痴呆的敏感性和特异性在舒尔曼量表上分别为90%和42%，在桑德兰量表上分别为74%和44%，在沃尔夫 - 克莱因量表上分别为48%和90%。
非痴呆老年人的画钟能力受教育程度影响。沃尔夫 - 克莱因评分方法受教育程度影响最小，检测痴呆的特异性最高，但敏感性较低。在受教育程度低的人群中，教育因素使得画钟作为痴呆单一筛查测试效果不佳。
