Background: Epidemiologic studies indicate that chronic cough and sputum production are associated with increased mortality and disease progression in COPD subjects. Our objective was to identify features associated with chronic cough and sputum production in COPD subjects.
Methods: Cross-sectional analysis of data were obtained in a multicenter (17 university hospitals in France) cohort of COPD patients. The cohort comprised 433 COPD subjects (65 +/- 11 years; FEV(1), 50 +/- 20% predicted). Subjects with (n = 321) and without (n = 112) chronic cough and sputum production were compared.
Results: No significant difference was observed between groups for age, FEV(1), body mass index, and comorbidities. Subjects with chronic cough and sputum production had increased total mean numbers of exacerbations per patient per year (2.20 +/- 2.20 vs 0.97 +/- 1.19, respectively; p < 0.0001), moderate exacerbations (1.80 +/- 2.07 vs 0.66 +/- 0.85, respectively; p < 0.0001), and severe exacerbations requiring hospitalizations (0.43 +/- 0.95 vs 0.22 +/- 0.56, respectively; p < 0.02). The total number of exacerbations per patient per year was the only variable independently associated with chronic cough and sputum production. Frequent exacerbations (two or more per patient per year) occurred in 55% vs 22% of subjects, respectively, with and without chronic cough and sputum production (p < 0.0001). Chronic cough and sputum production and decreased FEV(1) were independently associated with an increased risk of frequent exacerbations and frequent hospitalizations.
Conclusions: Chronic cough and sputum production are associated with frequent COPD exacerbations, including severe exacerbations requiring hospitalizations.