Abstract：
Postural Orthostatic Tachycardia Syndrome (POTS) presents with a range of poorly delineated symptoms across several domains. There is an urgent need for standardized symptom reporting in POTS, but a lack of validated symptom burden instruments. Our aim was to evaluate the psychometric properties of two symptom burden measures: the Orthostatic Grading Scale (OGS) and the Symptom Screen for Small-Fiber Polyneuropathy (SSS), in patients under investigation for suspected POTS.
Psychometric validation study.
Confirmatory factor analysis (CFA) tested the factor structure of the SSS and OGS completed by 149 patients under investigation for POTS. Scale reliability and validity were assessed. The uni-dimensionality of the SSS was assessed through principal component analysis (PCA).
CFA of the OGS revealed that a 1-factor structure had adequate fit. CFA of the SSS revealed that a 5-factor structure had generally appropriate fit supporting the originally proposed 5 factors (1: Gastrointestinal, 2: Somatosensory, 3: Miscellaneous, 4: Microvascular, and 5: Urological). In addition, the SSS demonstrated sufficient uni-dimensionality in the PCA, warranting use of a single total score. Omega coefficients of both measures indicated satisfactory internal reliability (0.668-0.931). Correlations with related constructs (distress (K10 score), r = 0.317-0.404, p < 0.001) and heart rate indices (with the OGS, r = 0.211-0.294, p < 0.05) suggested sound convergent and divergent validity.
Initial evidence suggests that the OGS and SSS have good psychometric properties for use in populations with suspected and confirmed POTS.
Psychometric validation study.
Confirmatory factor analysis (CFA) tested the factor structure of the SSS and OGS completed by 149 patients under investigation for POTS. Scale reliability and validity were assessed. The uni-dimensionality of the SSS was assessed through principal component analysis (PCA).
CFA of the OGS revealed that a 1-factor structure had adequate fit. CFA of the SSS revealed that a 5-factor structure had generally appropriate fit supporting the originally proposed 5 factors (1: Gastrointestinal, 2: Somatosensory, 3: Miscellaneous, 4: Microvascular, and 5: Urological). In addition, the SSS demonstrated sufficient uni-dimensionality in the PCA, warranting use of a single total score. Omega coefficients of both measures indicated satisfactory internal reliability (0.668-0.931). Correlations with related constructs (distress (K10 score), r = 0.317-0.404, p < 0.001) and heart rate indices (with the OGS, r = 0.211-0.294, p < 0.05) suggested sound convergent and divergent validity.
Initial evidence suggests that the OGS and SSS have good psychometric properties for use in populations with suspected and confirmed POTS.
摘要：
目的：体位性心动过速综合征（POTS）在多个领域表现出一系列不良症状。在POTS中迫切需要标准化的症状报告，但缺乏有效的症状负担工具。我们的目的是评估两种症状负担指标的心理测量特性：体位评分量表（OGS）和小纤维性多发性神经病（SSS）的症状筛查，在接受疑似POTS调查的患者中。
方法：心理测量验证研究。
方法：验证性因素分析（CFA）测试了149名POTS患者完成的SSS和OGS的因子结构。评估量表的信度和效度。通过主成分分析(PCA)评估SSS的单维性。
结果：OGS的CFA显示1因素结构具有足够的拟合。SSS的CFA显示，5因素结构通常具有适当的拟合，支持最初提出的5个因素（1：胃肠道，2：体感，3：杂项，4：微血管，和5：泌尿科）。此外,SSS在PCA中表现出足够的单维性，保证使用单一总分。两种措施的Omega系数均表明令人满意的内部可靠性（0.668-0.931）。与相关结构的相关性(遇险(K10评分)，r=0.317-0.404，p<0.001)和心率指数(使用OGS，r=0.211-0.294，p<0.05)表明声音收敛和发散的有效性。
结论：初步证据表明，OGS和SSS具有良好的心理测量特性，适用于怀疑和确认POTS的人群。
方法：心理测量验证研究。
方法：验证性因素分析（CFA）测试了149名POTS患者完成的SSS和OGS的因子结构。评估量表的信度和效度。通过主成分分析(PCA)评估SSS的单维性。
结果：OGS的CFA显示1因素结构具有足够的拟合。SSS的CFA显示，5因素结构通常具有适当的拟合，支持最初提出的5个因素（1：胃肠道，2：体感，3：杂项，4：微血管，和5：泌尿科）。此外,SSS在PCA中表现出足够的单维性，保证使用单一总分。两种措施的Omega系数均表明令人满意的内部可靠性（0.668-0.931）。与相关结构的相关性(遇险(K10评分)，r=0.317-0.404，p<0.001)和心率指数(使用OGS，r=0.211-0.294，p<0.05)表明声音收敛和发散的有效性。
结论：初步证据表明，OGS和SSS具有良好的心理测量特性，适用于怀疑和确认POTS的人群。
