Figure 1From: Cough in chronic obstructive pulmonary disease: is it important and what are the effects of treatment?Capsaicin cough sensitivity in COPD, asthma and healthy subjects. The cumulative frequency of responders defined as 5 coughs evoked by that concentration of inhaled capsaicin. Populations reflect healthy normal subjects, and patients with COPD or chronic stable asthma.Back to article page