Department of Psychology, University of California, Los Angeles, CA 90095, USA.
Psychol Assess. 2011 Mar;23(1):245-61. doi: 10.1037/a0021501.
A psychometric analysis of 2 interview-based measures of cognitive deficits was conducted: the 21-item Clinical Global Impression of Cognition in Schizophrenia (CGI-CogS; Ventura et al., 2008), and the 20-item Schizophrenia Cognition Rating Scale (SCoRS; Keefe et al., 2006), which were administered on 2 occasions to a sample of people with schizophrenia. Traditional psychometrics, bifactor analysis, and item response theory methods were used to explore item functioning and dimensionality and to compare instruments. Despite containing similar item content, responses to the CGI-CogS demonstrated superior psychometric properties (e.g., higher item intercorrelations, better spread of ratings across response categories) relative to the SCoRS. The authors argue that these differences arise mainly from the differential use of prompts and how the items are phrased and scored. Bifactor analysis demonstrated that although both measures capture a broad range of cognitive functioning (e.g., working memory, social cognition), the common variance on each is overwhelmingly explained by a single general factor. Item response theory analyses of the combined pool of 41 items showed that measurement precision is peaked in the mild to moderate range of cognitive impairment. Finally, simulated adaptive testing revealed that only about 10 to 12 items are necessary to achieve latent trait level estimates with reasonably small standard errors for most individuals. This suggests that these interview-based measures of cognitive deficits could be shortened without loss of measurement precision.
对 2 种基于访谈的认知缺陷测量工具进行了心理计量学分析：21 项精神分裂症临床整体印象认知量表（CGI-CogS；Ventura 等人，2008 年）和 20 项精神分裂症认知评定量表（SCoRS；Keefe 等人，2006 年），对精神分裂症患者样本进行了 2 次测试。传统心理计量学、双因素分析和项目反应理论方法用于探索项目功能和维度，并比较工具。尽管包含相似的项目内容，但 CGI-CogS 的反应表现出更好的心理计量学特性（例如，更高的项目相关性，在反应类别中更好地分布评分），而 SCoRS 则较差。作者认为这些差异主要源于提示的不同使用方式以及项目的措辞和评分方式。双因素分析表明，尽管这两种测量工具都可以捕捉广泛的认知功能（例如工作记忆、社会认知），但每个测量工具的共同方差主要由一个单一的一般因素解释。对 41 个项目的综合池的项目反应理论分析表明，在认知障碍的轻度至中度范围内，测量精度达到峰值。最后，模拟自适应测试表明，对于大多数个体，仅需要大约 10 到 12 个项目即可在较小的标准误差下达到潜在特质水平的估计。这表明这些基于访谈的认知缺陷测量工具可以缩短，而不会降低测量精度。
