Loubert Angely, Regnault Antoine, Meunier Juliette, Gutzwiller Florian S, Regnier Stéphane A
Modus Outcomes, Lyon, France.
Novartis Pharma AG, Basel, Switzerland.
Int J Chron Obstruct Pulmon Dis. 2020 Sep 8;15:2103-2113. doi: 10.2147/COPD.S261919. eCollection 2020.
The objective of this study was to examine the psychometric properties of the St. George's Respiratory Questionnaire (SGRQ) in patients with chronic obstructive pulmonary disease (COPD) using Rasch measurement theory (RMT) analyses.
RMT analysis was conducted on the baseline SGRQ data from five multi-national, Phase III randomized trials investigating a fixed-dose combination of a long-acting β2-agonist and a long-acting muscarinic antagonist in COPD patients. Analysis was performed for the SGRQ "Symptoms" and "Activity" domains. An exploratory analysis was also conducted using the different specific symptoms as defined in the reconceptualization of the SGRQ "Symptoms" domain. Differential item functioning (DIF) analysis was performed for geographical regions on the "Activity" domain, in order to explore cross-cultural validity of the SGRQ.
Overall, the SGRQ "Activity" domain showed good measurement property, but two items ("Sitting or lying still making feel breathless" and "Playing sports or game making feel breathless") showed very high fit residuals. The SGRQ "Symptoms" domain demonstrated good targeting; however, two items showed disordered thresholds ("Coughed" and "Brought up phlegm"). In an exploratory RMT analysis, measures for "Cough and Sputum", "Breathing difficulties" or "Wheezing attacks" showed unsatisfactory measurement properties with poor reliability (person separation index = 0.35, 0.66 and 0.16, respectively) and targeting issues. The examination of cross-cultural performances of the SGRQ "Activity" items showed a great variability in the responses to these items in different global regions.
Our results indicated that SGRQ may not be an appropriate instrument to measure symptom severity or activity limitations in patients with COPD. Hence, there is a need to develop other relevant PRO instruments that can be used in conjunction with SGRQ to provide a holistic assessment of the health status of COPD patients in clinical research.
本研究的目的是使用拉施测量理论（RMT）分析来检验圣乔治呼吸问卷（SGRQ）在慢性阻塞性肺疾病（COPD）患者中的心理测量特性。
对五项多国III期随机试验的基线SGRQ数据进行RMT分析，这些试验研究了长效β2受体激动剂和长效毒蕈碱拮抗剂的固定剂量组合在COPD患者中的应用。对SGRQ的“症状”和“活动”领域进行了分析。还使用SGRQ“症状”领域重新概念化中定义的不同特定症状进行了探索性分析。对“活动”领域的地理区域进行了差异项目功能（DIF）分析，以探索SGRQ的跨文化有效性。
总体而言，SGRQ“活动”领域显示出良好的测量特性，但有两个项目（“坐着或躺着不动会感到呼吸困难”和“进行体育活动或游戏会感到呼吸困难”）显示出非常高的拟合残差。SGRQ“症状”领域显示出良好的针对性；然而，有两个项目显示出阈值紊乱（“咳嗽”和“咳痰”）。在探索性RMT分析中，“咳嗽和咳痰”、“呼吸困难”或“喘息发作”的测量指标显示出不令人满意的测量特性，可靠性较差（个人分离指数分别为0.35、0.66和0.16）以及针对性问题。对SGRQ“活动”项目的跨文化表现检查显示，不同全球区域对这些项目的反应存在很大差异。
我们的结果表明，SGRQ可能不是测量COPD患者症状严重程度或活动受限的合适工具。因此，需要开发其他相关的患者报告结局（PRO）工具，可与SGRQ结合使用，以在临床研究中对COPD患者的健康状况进行全面评估。
