Mortality in GOLD stages of COPD and its dependence on symptoms of chronic bronchitis
Background: The GOLD classification of COPD severity introduces a stage 0 ( at risk) comprising individuals with productive cough and normal lung function. The aims of this study were to investigate total mortality risks in GOLD stages 0 - 4 with special focus on stage 0, and furthermore to assess the influence of symptoms of chronic bronchitis on mortality risks in GOLD stages 1 - 4. Method: Betw
