Scanlan J, Borson S
Alzheimer's Disease Research Center, University of Washington School of Medicine, 1959 NE Pacific Street, Seattle, WA 98195-6560, USA.
Int J Geriatr Psychiatry. 2001 Feb;16(2):216-22. doi: 10.1002/1099-1166(200102)16:2<216::aid-gps316>3.0.co;2-b.
As elderly populations grow, dementia detection in the community is increasingly needed. Existing screens are largely unused because of time and training requirements. We developed the Mini-Cog, a brief dementia screen with high sensitivity, specificity, and acceptability. Here we describe the development of its scoring algorithm, its receiver operating characteristics (ROC), and the generalizability of its clock drawing scoring system.
A total of 249 multi-lingual older adults were examined. Scores on the three-item recall task and the clock drawing task (CDT-CERAD version) were combined to create an optimal algorithm. Receiver operating characteristics for seven alternatives were compared with those of the MMSE and the CASI using expert raters. To assess the CDT scoring generalizability, 20 naïve raters, without explicit instructions or prior CDT exposure, scored 80 randomly selected clocks as "normal" or "abnormal" (20 from each of four CERAD categories).
An algorithm maximizing sensitivity and correct diagnosis was defined. Its ROC compared favorably with those of the MMSE and CASI. CDT concordance between naïve and trained raters was >98% for normal, moderately and severely impaired clocks, but lower (60%) for mildly impaired clocks. Recalculation of the Mini-Cog's performance, assuming that naïve raters would score all mildly impaired CDTs in the full sample as normal, retained high sensitivity (97%) and specificity (95%).
The Mini-Cog algorithm performs well with simple clock scoring techniques. The results suggest that the Mini-Cog may be used successfully by relatively untrained raters as a first-stage dementia screen. Further research is needed to characterize the Mini-Cog's utility when population dementia prevalences are low.
随着老年人口的增长，社区中的痴呆症检测需求日益增加。由于时间和培训要求，现有的筛查方法大多未被使用。我们开发了简易认知评估量表（Mini-Cog），这是一种具有高灵敏度、特异性和可接受性的简短痴呆症筛查工具。在此，我们描述其评分算法的开发、其受试者工作特征（ROC）以及其画钟评分系统的可推广性。
共检查了249名多语言老年人。将三项回忆任务和画钟任务（CERAD版本）的得分相结合，以创建一种最佳算法。使用专家评分者将七种替代方法的受试者工作特征与简易精神状态检查表（MMSE）和认知能力筛查量表（CASI）的特征进行比较。为了评估画钟任务评分的可推广性，20名未经过明确指导或之前未接触过画钟任务的初级评分者，将80个随机选择的时钟评为“正常”或“异常”（四个CERAD类别中每个类别各20个）。
定义了一种使灵敏度和正确诊断最大化的算法。其ROC优于MMSE和CASI。对于正常、中度和重度受损的时钟，初级评分者与训练有素的评分者之间的画钟任务一致性>98%，但对于轻度受损的时钟，一致性较低（60%）。假设初级评分者将全样本中所有轻度受损的画钟任务都评为正常，重新计算简易认知评估量表的性能，其仍保持高灵敏度（97%）和特异性（95%）。
简易认知评估量表算法在简单的画钟评分技术下表现良好。结果表明，相对未经培训的评分者可以成功地将简易认知评估量表用作痴呆症的第一阶段筛查工具。当人群痴呆症患病率较低时，需要进一步研究以确定简易认知评估量表的效用。
