Inter-relationship of different types of respiratory symptoms in COPD
European Respiratory Journal(2014)
摘要
Aim To examine the relationship between respiratory symptoms and their consistency across subgroups. Methods Data were analysed from two, 6-month aclidinium/formoterol combination studies. Respiratory symptoms were assessed by the Exacerbations of Chronic Pulmonary Disease Tool-Respiratory Symptoms (E-RS), the Early Morning Symptoms of COPD questionnaire and the Nighttime Symptoms of COPD questionnaire. The latter both evaluate individual symptoms (cough, wheezing, shortness of breath and difficulty bringing-up phlegm) and have an overall COPD symptoms item; also assessed were: limitation to activity (morning) and nocturnal awakening due to COPD (nighttime). Subgroups tested were sex, age, smoking status, severity of airway obstruction (postbronchodilator FEV 1 /FVC 1 ≥50% predicted or postbronchodilator FEV 1 /FVC 1 Results The worst scores were: breathlessness, and early morning and nighttime cough and breathlessness. Two factors account for 83% of variance (F1: 72%; F2: 11%). F1 consisted of wheezing, breathlessness, overall COPD symptoms and limitation of activity; F2 contained cough and phlegm. Morning, daytime or night symptoms always loaded onto the same factor. Subgroups had the same pattern except GOLD A and C. In GOLD A, F1 (60% variance) was driven by cough and phlegm, and F2 (16% variance) by breathlessness. In GOLD C, F1 (57% variance) consisted of breathlessness, wheezing and awakenings; F2 (16% variance) contained cough and overall COPD symptoms. Conclusions Most COPD symptoms, regardless of time of day, group into a single factor; cough and phlegm form a second factor.
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关键词
respiratory symptoms,copd,inter-relationship
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