Paganini-Hill A, Clark L J, Henderson V W, Birge S J
Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
J Am Geriatr Soc. 2001 Jul;49(7):941-7. doi: 10.1046/j.1532-5415.2001.49185.x.
To test the hypothesis that performance on a clock-drawing test in a mailed survey to an older cohort is associated with known and potential risk and protective factors for Alzheimer's disease.
The Leisure World Cohort Study is an ongoing study, begun in 1981, of nearly 14,000 older adults. In November 1992, the 8,406 living cohort members were mailed a follow-up questionnaire.
Leisure World Laguna Hills, a southern California retirement community.
The study population is a predominantly white, well-educated, upper-middle-class community; approximately two-thirds are women. Data from 4,843 cohort members (mean age 80 years; range 52-101) were analyzed.
The questionnaire included a clock-drawing task: a predrawn circle 3 1/4 inches (8.3 cm) in diameter was provided with instructions "In the circle below, draw in the numbers as on a clock face. Make no erasures." Clocks were scored on 7 items: all numbers 1-12 present without adding extra or omitting numbers, sequencing of numbers, position of numbers, orientation of numbers to circle, consistent number style (either Arabic or Roman), tilt of numbers, and superfluous marks. A total clock score was calculated by summing the number of correct individual items (0-7). We also classified individuals as cognitively impaired by a previously suggested method: individuals were affected if they did not have three numbers drawn in the upper left quadrant of the clock face.
Ninety percent or more of the participants across all ages placed the numbers 1 to 12 on their clocks without omissions or additions; 35% completed the clock drawing without error. The mean total clock scores decreased with each successive 5-year age group in both men and women. Regression analysis indicated a significant effect for age (b = -0.15, P <.0001), education (b = 0.05, P =.0001), smoking (b = 0.13, P =.03), and female gender (b = -0.05, P =.05) and a marginally significant effect of nonrheumatoid arthritis (b = 0.05, P =.07) on total clock score. No other measured variable had a significant effect. Cognitively impaired individuals were more likely to be female and older. After adjusting for age and gender, they were also more likely to be hypertensive and to have taken blood pressure medication and less likely to be college graduates, have glaucoma or arthritis, and to have taken vitamin supplements.
The clock-drawing task is an appealing measure of cognitive function for large epidemiological studies because it is a simple, self-administered test that is easily adapted to mail surveys and correlates with more-detailed and more-time-consuming cognitive screens. Although it is relatively free of influence by language, cultural, or ethnic factors, our study shows that even in a highly educated population, clock drawing is influenced by educational level and other known risk factors for Alzheimer's disease. Thus a clock-drawing task may help predict cognitive frailty and future disability in older people. Such determination can direct high-risk individuals to earlier diagnosis, potential therapies, and better management.
检验以下假设：在针对老年人群体的邮寄调查中，画钟测试的表现与阿尔茨海默病已知和潜在的风险及保护因素相关。
休闲世界队列研究是一项始于1981年的正在进行的研究，涉及近14000名老年人。1992年11月，向8406名在世的队列成员邮寄了一份随访问卷。
加利福尼亚州南部的退休社区休闲世界拉古纳希尔斯。
研究人群主要是白人、受过良好教育、中上层阶级社区；约三分之二为女性。分析了4843名队列成员（平均年龄80岁；范围52 - 101岁）的数据。
问卷包括一项画钟任务：提供一个预先画好的直径为3又1/4英寸（8.3厘米）的圆圈，并附有说明“在下面的圆圈中，按照钟面的样子画出数字。不要擦除。”根据7个项目对画钟进行评分：1 - 12所有数字都有且无额外添加或遗漏、数字顺序、数字位置、数字与圆圈的方向、一致的数字样式（阿拉伯数字或罗马数字）、数字倾斜度以及多余标记。通过将正确的单个项目数量（0 - 7）相加计算出画钟总分。我们还采用先前建议的方法将个体分类为认知受损：如果个体在钟面的左上象限没有画出三个数字，则判定为受影响。
所有年龄段90%或更多的参与者在画钟时写出了1到12的数字，没有遗漏或添加；35%的人正确完成了画钟。男性和女性的平均画钟总分均随着每一个连续的5岁年龄组而下降。回归分析表明，年龄（b = -0.15，P <.0001）、教育程度（b = 0.05，P =.0001）、吸烟（b = 0.13，P =.03）和女性性别（b = -0.05，P =.05）对画钟总分有显著影响，非类风湿性关节炎（b = 0.05，P =.07）对画钟总分有边缘显著影响。其他测量变量均无显著影响。认知受损个体更可能是女性且年龄较大。在调整年龄和性别后，他们也更可能患有高血压且服用过血压药物，不太可能是大学毕业生，患有青光眼或关节炎，以及服用过维生素补充剂。
画钟任务对于大型流行病学研究来说是一种有吸引力的认知功能测量方法，因为它是一种简单的自我管理测试，很容易适用于邮寄调查，并且与更详细、更耗时的认知筛查相关。尽管它相对不受语言、文化或种族因素的影响，但我们的研究表明，即使在受过高等教育的人群中，画钟也受到教育水平和其他已知的阿尔茨海默病风险因素的影响。因此，画钟任务可能有助于预测老年人的认知脆弱性和未来的残疾情况。这样的判定可以引导高危个体进行早期诊断、潜在治疗和更好的管理。
