Figure 2

COPD prevalence and underdiagnosis according to (A) gender and smoking status, and (B) age categories. COPD, chronic obstructive pulmonary disease; CS, current smokers; FS, former smokers; NS, non-smokers; OLD, obstructive lung disease. The grey parts of the bar represent the proportion of patients with COPD based on spirometry who did not have a history of OLD (i.e. previously underdiagnosed patients).