Productive cough is an independent risk factor for the development of COPD in former smokers

Abstract

Productive cough was an independent risk factor for the development of COPD in Japanese men. In particular, former smokers who complain of this symptom should be regarded as being at high risk for the development of COPD. The data suggested that stage 0 disease, as defined in the Global Initiative for Chronic Obstructive Lung Disease 2001 guidelines, is relevant for the identification of subjects at risk of developing COPD.