Cullen Breda, Fahy Sabina, Cunningham Conal J, Coen Robert F, Bruce Irene, Greene Elaine, Coakley Davis, Walsh J Bernard, Lawlor Brian A
Mercer's Institute for Research on Ageing, St James's Hospital, Dublin 8, Ireland.
Int J Geriatr Psychiatry. 2005 Apr;20(4):371-6. doi: 10.1002/gps.1291.
The MMSE is a widely-used instrument in screening for dementia in the community. The traditional cut-point of <24/30 may be unsuitable for use in some settings, due to biases in age and education.
This study aimed to investigate whether cut-points derived from age- and education-specific norms would improve the performance of the MMSE as a screening tool for dementia and cognitive impairment in an Irish community setting, potentially reducing the number of onward referrals. A secondary aim was to obtain score norms in an Irish sample.
One thousand one hundred and fifteen people aged over 65 (mean age 74.8+/-6.8 years; 68% female) were assessed in their own homes, using MMSE (world) and the AGECAT computerised diagnostic system for mental illness in the elderly. The performance of the MMSE in identifying case- and sub-case-level dementia was investigated using cut-points of <24 and <23, as well as adjusted cut-points based on published norms and norms derived from the Irish sample.
Published norms did not prove useful in improving screening accuracy. Cut-points based on 10th percentile Irish norms and the <23 cut-point performed comparably well, both yielding 93% specificity, with overall accuracy of 90% and 91% respectively (as sensitivity was higher for the <23 cut-point).
Locally-derived norms yielded better screening accuracy than did published norms or the traditional <24 cut-point. The importance of selecting an appropriate percentile cut-off when using norms is discussed. The best results were obtained with a simple <23 cut-point, and this may be optimal when screening for dementia in an Irish community setting.
简易精神状态检查表（MMSE）是社区中广泛用于筛查痴呆症的工具。由于年龄和教育方面的偏差，传统的临界值<24/30可能不适用于某些情况。
本研究旨在调查根据年龄和教育程度特定规范得出的临界值是否能提高MMSE作为爱尔兰社区环境中痴呆症和认知障碍筛查工具的性能，从而可能减少进一步转诊的人数。第二个目的是获得爱尔兰样本中的分数规范。
对1115名65岁以上的人（平均年龄74.8±6.8岁；68%为女性）在其家中进行评估，使用MMSE（通用版）和用于老年人精神疾病的AGECAT计算机诊断系统。使用<24和<23的临界值，以及基于已发表规范和爱尔兰样本得出的规范的调整后临界值，研究MMSE在识别病例级和亚病例级痴呆症方面的性能。
已发表的规范在提高筛查准确性方面未被证明有用。基于爱尔兰第10百分位数规范的临界值和<23的临界值表现相当，特异性均为93%，总体准确率分别为90%和91%（因为<23的临界值敏感性更高）。
本地得出的规范比已发表的规范或传统的<24临界值产生了更好的筛查准确性。讨论了使用规范时选择合适百分位数临界值的重要性。使用简单的<23临界值获得了最佳结果，在爱尔兰社区环境中筛查痴呆症时这可能是最佳的。
