Classification of chronic obstructive pulmonary disease (COPD) is usually based on the severity of airflow limitation, which may not reflect phenotypic heterogeneity. Here, we sought to identify COPD phenotypes using multiple clinical variables.COPD subjects recruited in a French multicentre cohort were characterised using a standardised process. Principal component analysis (PCA) was performed using eight variables selected for their relevance to COPD: age, cumulative smoking, forced expiratory volume in 1 s (FEV1) (% predicted), body mass index, exacerbations, dyspnoea (modified Medical Research Council scale), health status (St George's Respiratory Questionnaire) and depressive symptoms (hospital anxiety and depression scale). Patient classification was performed using cluster analysis based on PCA-transformed data.322 COPD subjects were analysed: 77% were male; median (interquartile range) age was 65.0 (58.0-73.0) yrs; FEV1 was 48.9 (34.1-66.3)% pred; and 21, 135, 107 and 59 subjects were classified in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1, 2, 3 and 4, respectively. PCA showed that three independent components accounted for 61% of variance. PCA-based cluster analysis resulted in the classification of subjects into four clinical phenotypes that could not be identified using GOLD classification. Importantly, subjects with comparable airflow limitation (FEV1) belonged to different phenotypes and had marked differences in age, symptoms, comorbidities and predicted mortality.These analyses underscore the need for novel multidimensional COPD classification for improving patient care and quality of clinical trials.
These data suggest that in the presence of dyspnea and exacerbation, depression is the most important contributor to HRQoL impairment measured by SGRQ in COPD subjects, whereas other comorbidities and FEV(1) have only limited impact.
In patients with COPD, there is controversy regarding the association of blood eosinophil (Eos) levels with 1) exacerbation frequency and 2) the effect of inhaled corticosteroids for prevention of exacerbations. To determine whether Eos define subgroups of patients exhibiting attributes of COPD clinical phenotypes, we compared clinical features and mortality rates in COPD patients from the Initiatives BPCO French cohort categorized using different thresholds of blood Eos levels. The following data were collected at inclusion: medical and smoking history, occupational exposures, dyspnea, cough and sputum production, exacerbations in the previous year, history of allergy and asthma, nasal symptoms, body mass index, St George Respiratory Questionnaire (SGRQ) total score, post-bronchodilator spirometry, comorbidities, and medications. Three-year survival between groups was compared using Kaplan–Meier analysis. Three sets of analyses were performed to compare patients with ≥2% versus <2%, ≥3% versus <3%, and ≥4% versus <4% Eos. Eos was available in 458 patients (mean age: 62 years, 72% male, mean forced expiratory volume in 1 second: 51% pred), including 235 patients with Eos ≥2% (49%), 149 with Eos ≥3% (33%), and 90 with Eos ≥4% (20%). For all cutoffs, there was no difference between Eos+ and Eos− groups in univariate analyses except for diabetes and SGRQ score (more frequent and more impaired, respectively, in lower Eos categories). In particular, there was no difference in exacerbation rate, history of asthma, or three-year survival. In conclusion, regardless of the cutoff, Eos+ COPD patients exhibited no specific characteristic in terms of symptoms, lung function, exacerbation rate, and prognosis. These findings suggest that the association of higher Eos with exacerbations reported in previous studies could be population specific, which does not support generalizing the use of Eos as a biomarker for COPD phenotyping.
BackgroundCough and sputum production are frequent in chronic obstructive pulmonary disease (COPD). The objective of this study was to examine the relationship between cough and sputum production and health-related quality of life in COPD.MethodsA cross-sectional study was conducted in the French Initiatives COPD cohort and assessed cough and sputum production within the past 7 days using the cough and sputum assessment questionnaire (CASA-Q), health-related quality of life, spirometry, smoking status, dyspnea, exacerbations, anxiety and depression, and comorbidities.ResultsOne hundred and seventy-eight stable COPD patients were included (age, 62 [56–69] years, 128 male, forced expiratory volume in 1 second [FEV1]: 57 [37–72] % predicted) (median [Q1–Q3]). In univariate analyses, health-related quality of life (Saint George’s respiratory questionnaire total score) was associated with each CASA-Q domain and with chronic bronchitis, exacerbations, dyspnea, FEV1, depression, and anxiety. All four domains introduced separately were independently associated with health-related quality of life. When introduced together in multivariate analyses, only the cough impact domain remained independently associated with health-related quality of life (R2=0.60). With chronic bronchitis (standard definition) instead of the CASA-Q, the R2 was lower (R2=0.54).ConclusionThis study provides evidence that current cough in the previous 7 days is an important determinant of health-related quality of life impairment in stable COPD patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.