Tsai Rung-Ching, Lin Ker-Neng, Wang Hsiao-Jyuan, Liu Hsiu-Chih
Department of Mathematics, National Taiwan Normal University, Taipei, Taiwan.
Int Psychogeriatr. 2007 Dec;19(6):1051-63. doi: 10.1017/S1041610207005327. Epub 2007 Apr 23.
The Cognitive Abilities Screening Instrument (CASI) consists of items which are designed to measure the nine domains of cognitive ability. Its total score is used clinically to represent the overall underlying cognitive ability of the patient. This study aimed to evaluate the justification of the uses of the all-domain-total-score as an overall cognitive measure and the domain scores as measures of designated individual cognitive ability.
To justify the use of total score of all the items as an overall measure of cognitive ability, a second-order confirmatory factor analysis was performed to examine whether the items in CASI contributed significantly to a common underlying construct. The uses of domain scores were also examined by inspecting the loadings of the items on their designated domains. The CASI data from 608 patients, 68 normal and 540 with Alzheimer's disease, were analyzed.
The goodness-of-fit indices for the second-order factor model were as follows: CFI was 0.912 for WLSMV and 0.977 for WLSM; TLI and RMSEA values were 0.975 and 0.090 respectively. The loadings of the items on the common underlying construct are all salient (>0.3). The loadings of all but the long-term memory items on their respective subdomains were also salient.
The items of the CASI C-2.0 were useful not only in profiling the correlated cognitive domain scores, but also in forming an overall measure of the underlying cognitive ability of the patients.
认知能力筛查工具（CASI）由旨在测量九个认知能力领域的项目组成。其总分在临床上用于代表患者潜在的整体认知能力。本研究旨在评估将所有领域总分用作整体认知指标以及将领域分数用作特定个体认知能力指标的合理性。
为了证明将所有项目的总分用作认知能力的整体指标的合理性，进行了二阶验证性因素分析，以检验CASI中的项目是否对一个共同的潜在结构有显著贡献。还通过检查项目在其指定领域的负荷来检验领域分数的用途。对608名患者（68名正常人和540名阿尔茨海默病患者）的CASI数据进行了分析。
二阶因素模型的拟合优度指标如下：WLSMV的CFI为0.912，WLSM的CFI为0.977；TLI和RMSEA值分别为0.975和0.090。项目在共同潜在结构上的负荷均显著（>0.3）。除长期记忆项目外，所有项目在各自子领域的负荷也显著。
CASI C - 2.0的项目不仅有助于描绘相关的认知领域分数，还有助于形成对患者潜在认知能力的整体测量。
