重症肌无力患者报告结局指标量表的研制——计量心理学测评

目的：为考察用于中西医临床疗效评价的重症肌无力（myasthenia gravis, MG）患者报告结局指标（patient-reported outcome, PRO）量表的科学性，对其计量心理学特征进行评价。 方法：用MG-PRO量表对200例样本（100名健康人和100名重症肌无力患者）进行自评量表式调查，应用经典测量理论和项目反应理论方法对其信度、效度、个体差异指数和条目功能差异（differential item functioning, DIF）等计量心理学特征进行考评。 结果：经典测量理论分析结果显示，总量表以及各领域的分半信度系数大于0.7，各领域Cronbach＇s α系数大于0.80；每个方面与其所属领域的相关系数均大于其与其他领域的相关系数。从结构效度来看，探索性因子分析提取出4个主成分，反映了生理、心理、社会、治疗4个领域，累计贡献率为55.54%；重症肌无力患者与健康人在每个方面的测评结果比较，差异均有统计学意义（P〈0.01）。项目反应理论分析结果显示，每个模型的个体差异指数均大于0.8，所有条目都没有一致性DIF和非一致性DIF。 结论：MG-PRO量表反映了WHO关于生存质量的内涵和重症肌无力患者的特殊问题，而且具有良好的信度（分半信度、内部一致性信度）和效度（内容效度、结构效度、区分效度），具有良好的项目反应理论模型的计量心理学特征。

Development of patient-reported outcome scale for myasthenia gravis: a psychometric test

Objective： To investigate the scientificity of patient-reported outcome （PRO） scale for myasthenia gravis （MG）, which was used to evaluate the clinical effects of traditional Chinese and Western medicine treatment on MG patients. Psychometric performance of the MG-PRO scale was also expected to be evaluated in this study.
Methods： A total of 100 MG patients and 100 healthy people were face-to-face interviewed by well-trained investigators, and the data of MG-PRO scale were collected. The classical theory test （CTT） and item response theory （IRT） methods were used to analyze the psychometric performance such as validity, reliability, person separation index （PSI） and differential item functioning （DIF） in the MG-PRO scale.
Results： The results of CTT analysis showed that the split-half reliabilities of the MG-PRO scale and each dimension were greater than 0.7. In the analysis of internal consistency of each dimension, the Cronbach＇s α was greater than 0.8. Each facet had greater correlation with its dimension than the other dimensions. Four principal components were extracted by exploratory factor analysis, which represented all dimensions of the scale, and the cumulative variance was 55.54%. The scores of each of the 8 facets between MG patients and healthy people were different （P〈0.01）. The results of IRT showed that the PSI of each model was greater than 0.8, and all items did not have uniform DIF and non-uniform DIF.
Conclusion： The MG-PRO scale reflects the definition and connotation of quality of life and contains special issues of MG patients as well, and shows good reliability （split-half reliability, Cronbach＇s α）, validity （content validity, construct validity, discriminate validity） from the results of CTT, and good psychometric performance from the results of IRT.