Wciórka J, Anczewska M, Bembenek A, Gołebiewska M, Hochlewicz A, Nurowska K, Schaeffer E, Skowrońska J, Stanikowska I, Tarczyńska K
I Kliniki Psychiatrycznej IPiN w Warszawie.
Psychiatr Pol. 2000 Mar-Apr;34(2):203-21.
The aim of the study was an evaluation of validity measures of the CASS (Clinical Assessment of Schizophrenic Syndromes)--a new multi-purpose and multi-level clinical diagnostic instrument consisting of a diagnostic questionnaire (CASS-D) allowing to analyze a diagnosis of schizophrenia according to DSM-IV and ICD-10 criteria as well as of three rating scales designed for description and intensity evaluation of schizophrenic syndromes on the global (CASS-G), dimensional (CASS-P, a profile of 13 basic dimensions) or symptomatological (CASS-S, a set of 31 symptoms) level.
194 inpatients consecutively admitted to the Department within approximately 6 months were assessed twice (at the start and end of their hospitalization) by 12 trained diagnosticians.
Several measures of validity were analyzed. Results obtained by means of CASS were compared with results of the SANS/SAPS, BPRS, and PANSS as reference rating scales (diagnostic validity). Characteristics of frequency, intensity, dynamics and specificity of scale items were used to analyze content validity. Factorial structure of CASS scales was applied as a measure of construct validity.
Diagnostic validity of the new instrument seems to be confirmed by its very high correlation coefficients with rating scales recognized as international standards: BPRS, PANSS, and SANS/SAPS. Reasonable characteristics of frequency, intensity, dynamics and specificity of individual items (dimensions, symptoms) and sum scores of CASS scales and relationships between their values strongly suggest their content validity. Both sum (CASS-P, CASS-S) and global (CASS-G) scores of scales under study revealed some specificity--they had significantly higher values in patients with schizophrenia than in patients with other diagnoses. It allows to distinguish in a schizophrenic syndrome described by CASS components which are specific and not specific for this disorder. The latter have been left also in the final version for their practical and clinical importance. Construct validity of the CASS was studied separately for different scales (CASS-P, CASS-S) and different groups (all or only schizophrenic patients) by means of several factor analyses, and performed along identical statistical procedure (principal component method of extraction with criterion eigenvalue > 1, followed by Equamax rotation). Resulting solutions could be interpreted reasonably and consistently with contemporary attempts to find adequate factorial models of intrinsic structure of schizophrenic syndrome. Thus they support confidence for constructive aspect of the CASS validity.
Ultimately, results obtained in the study suggest that the CASS may be considered as an instrument with some promising indices of diagnostic, content and construct validity, which may be potentially useful for clinical and research purposes.
本研究旨在评估CASS（精神分裂症综合征临床评估量表）的效度指标。CASS是一种新型的多用途、多层次临床诊断工具，由一份诊断问卷（CASS-D）组成，该问卷可根据《精神疾病诊断与统计手册》第四版（DSM-IV）和《国际疾病分类》第十版（ICD-10）标准分析精神分裂症的诊断，还包括三个用于在整体（CASS-G）、维度（CASS-P，13个基本维度的剖面图）或症状学（CASS-S，一组31种症状）层面描述和评估精神分裂症综合征强度的评定量表。
在大约6个月内连续入住该科室的194名住院患者由12名经过培训的诊断医生进行了两次评估（在住院开始和结束时）。
分析了几种效度指标。将通过CASS获得的结果与作为参考评定量表的SANS/SAPS、BPRS和PANSS的结果进行比较（诊断效度）。量表项目的频率、强度、动态变化和特异性特征用于分析内容效度。CASS量表的因子结构被用作结构效度的一种测量方法。
新工具的诊断效度似乎通过其与被公认为国际标准的评定量表（BPRS、PANSS和SANS/SAPS）的非常高的相关系数得到了证实。CASS量表各个项目（维度、症状）以及总分的频率、强度、动态变化和特异性的合理特征，以及它们之间数值的关系强烈表明了其内容效度。所研究量表的总分（CASS-P、CASS-S）和整体分（CASS-G）都显示出一定的特异性——它们在精神分裂症患者中的值显著高于其他诊断的患者。这使得能够在由CASS组件描述的精神分裂症综合征中区分出哪些是该疾病特有的和非特有的成分。后者因其实际和临床重要性也保留在了最终版本中。通过几种因子分析分别针对不同量表（CASS-P、CASS-S）和不同组（所有患者或仅精神分裂症患者）研究了CASS的结构效度，并按照相同的统计程序进行（采用特征值>1的主成分提取方法，随后进行等量最大旋转）。所得结果能够得到合理的解释，并且与当代寻找精神分裂症综合征内在结构适当因子模型的尝试一致。因此，它们支持了对CASS效度建设性方面的信心。
最终，本研究获得的结果表明，CASS可被视为一种具有一些诊断、内容和结构效度的有前景指标的工具，可能对临床和研究目的具有潜在用途。
