Severe Chronic Bronchitis in Advanced Emphysema Increases Mortality and Hospitalizations

Abstract

Background: Chronic bronchitis in COPD has been associated with an increased exacerbation rate, more hospitalizations, and an accelerated decline in lung function. The clinical characteristics of patients with advanced emphysema and chronic bronchitis have not been well described. Methods: Patients randomized to medical therapy in the National Emphysema Treatment Trial were grouped based on their reports of cough and phlegm on the St. George's Respiratory Questionnaire(SGRQ) at baseline: chronic bronchitis(CB+) and no chronic bronchitis(CB–). The patients were similarly categorized into severe chronic bronchitis(SCB+) or no severe chronic bronchitis (SCB–) based on the above definition plus report of chest trouble. Kaplan-Meier survival analysis was used to determine the relationships between chronic bronchitis and severe chronic bronchitis and survival and time to hospitalization. Lung function and SGRQ scores over time were compared between groups. Results: The CB+(N = 234; 38%) and CB- groups(N = 376; 62%) had similar survival (median 60.8 versus 65.7 months, p = 0.19) and time to hospitalization (median 26.9 versus 24.9 months, p = 0.84). The SCB+ group(N = 74; 12%) had worse survival (median 47.7 versus 65.7 months, p = 0.02) and shorter time to hospitalization (median 18.5 versus 26.7 months, p = 0.02) than the SCB- group (N = 536; 88%). Mortality and hospitalization rates were not increased when chest trouble was analyzed by itself. The CB+ and CB–groups had similar lung function and SGRQ scores over time. The SCB+ and SCB–groups had similar lung function over time, but the SCB+ group had significantly worse SGRQ scores. Conclusions: Severe chronic bronchitis is associated with worse survival, shorter time to hospitalization, and worse health-related quality of life.

Keywords :

• Chronic Bronchitis
• Chronic Obstructive Pulmonary Disease
• Emphysema
• National Emphysema Treatment Trial
• Mortality