Crawford John R, Garthwaite Paul H, Howell David C, Venneri Annalena
Department of Psychology, King's College, University of Aberdeen, Aberdeen, UK.
J Int Neuropsychol Soc. 2003 Nov;9(7):989-1000. doi: 10.1017/S1355617703970032.
Performance on some neuropsychological tests is best expressed as an intra-individual measure of association (such as a parametric or non-parametric correlation coefficient or the slope of a regression line). Examples of the use of intra-individual measures of association (IIMAs) include the quantification of performance on tests designed to assess temporal order memory or the accuracy of time estimation. The present paper presents methods for comparing a patient's performance with a control or normative sample when performance is expressed as an IIMA. The methods test if there is a significant difference between a patient's IIMA and those obtained from controls, yield an estimate of the abnormality of the patient's IIMA, and provide confidence limits on the level of abnormality. The methods can be used with normative or control samples of any size and will therefore be of particular relevance to single-case researchers. A method for comparing the difference between a patient's scores on two measures with the differences observed in controls is also described (one or both measures can be IIMAs). All the methods require only summary statistics (rather than the raw data from the normative or control sample); it is hoped that this feature will encourage the development of norms for tasks that use IIMAs to quantify performance. Worked examples of the statistical methods are provided using data from a clinical case and controls. A computer program (for PCs) that implements the methods is described and made available.
在一些神经心理学测试中，表现最好用个体内部关联度量来表示（例如参数或非参数相关系数或回归线的斜率）。使用个体内部关联度量（IIMA）的例子包括对旨在评估时间顺序记忆的测试表现或时间估计准确性的量化。本文介绍了在表现以IIMA表示时，将患者的表现与对照或常模样本进行比较的方法。这些方法测试患者的IIMA与从对照中获得的IIMA之间是否存在显著差异，得出患者IIMA异常程度的估计值，并提供异常水平的置信限。这些方法可用于任何规模的常模或对照样本，因此对单病例研究人员特别有意义。还描述了一种将患者在两项测量上的得分差异与在对照中观察到的差异进行比较的方法（一项或两项测量可以是IIMA）。所有方法仅需要汇总统计量（而不是来自常模或对照样本的原始数据）；希望这一特性将鼓励为使用IIMA量化表现的任务制定常模。使用来自一个临床病例和对照的数据提供了统计方法的实例。描述并提供了一个实现这些方法的计算机程序（适用于个人电脑）。
