Park Young-Jae
Department of Biofunctional Medicine and Diagnostics, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
Department of Diagnosis and Biofunctional Medicine, Kyung Hee University Hospital at Gangdong, No. 892 Dongnam-ro, Gangdong-Gu, Seoul 05278, Republic of Korea.
Evid Based Complement Alternat Med. 2021 Oct 28;2021:6528891. doi: 10.1155/2021/6528891. eCollection 2021.
The 25-item Phlegm Pattern Questionnaire (PPQ) has been widely used to examine the relationship between the phlegm pattern (PP), quality of life, tongue colour, vocal qualities, and dysfunctional breathing. However, the concerns of response burden and differences in the respondent's abilities or item difficulty for the original version of the PPQ have not been sufficiently addressed. This study aimed to develop a short-form PPQ using Rasch analysis, an item response theory. Based on the retrospective data, the response order, differential item functioning (DIF), dimensionality, reliability, concurrent validity, and fitting errors were examined for 291 normal participants and 61 inpatients. The discriminative ability of the short-form PPQ was examined using receiver operating characteristic curve analysis. Along with Rasch analysis, another short-form PPQ was developed using equidiscriminative item-total correlation (EITC) analysis and the results between the two short-form PPQs were compared accordingly. Rasch analysis results suggested a 6-point response category for the PPQ, and finally, 8 items without fitting errors or DIF variability were selected for the PPQ (PPQ-8). The PPQ-8 had satisfactory reliability (person separation index = 2.23), unidimensionality (unexplained variance in the first contrast = 1.598), fitting levels (infit mean square, 0.80-1.39; outfit mean square, 0.79-1.34), sensitivity (70.5%), and specificity (76.5%). The PPQ-8 had a moderate discriminative ability of the PP (area under the curve = 0.759), and the cut-off point was 23. Although the 8-item PPQ developed using EITC analysis showed similar levels of reliability, validity, and discriminative ability of the PP to the PPQ-8, it could not present the information of item hierarchy and differences in the respondents' abilities. In conclusion, the PPQ-8 by Rasch analysis is recommended for future use to evaluate the clinical severity of PP.
25项痰证问卷（PPQ）已被广泛用于研究痰证（PP）与生活质量、舌色、嗓音质量及呼吸功能障碍之间的关系。然而，原始版本的PPQ存在的应答负担问题以及应答者能力差异或项目难度问题尚未得到充分解决。本研究旨在运用项目反应理论中的Rasch分析开发一个简化版PPQ。基于回顾性数据，对291名正常参与者和61名住院患者的应答顺序、项目功能差异（DIF）、维度、信度、同时效度及拟合误差进行了检验。使用受试者工作特征曲线分析检验了简化版PPQ的鉴别能力。除了Rasch分析，还运用等鉴别力项目-总分相关（EITC）分析开发了另一个简化版PPQ，并对两个简化版PPQ的结果进行了比较。Rasch分析结果表明PPQ采用6点应答类别，最终为PPQ选择了8个无拟合误差或DIF变异性的项目（PPQ-8）。PPQ-8具有令人满意的信度（个人分离指数=2.23）、单维度性（第一对比中未解释方差=1.598）、拟合水平（内拟合均方，0.80 - 1.39；外拟合均方，0.79 - 1.34）、敏感性（70.5%）和特异性（76.5%）。PPQ-8对PP具有中等鉴别能力（曲线下面积=0.759），截断点为23。尽管使用EITC分析开发的8项PPQ在PP的信度、效度和鉴别能力水平上与PPQ-8相似，但它无法呈现项目层次信息和应答者能力差异。总之，建议未来使用经Rasch分析的PPQ-8来评估PP的临床严重程度。
