Table 1. Demographics and baseline characteristics of patients with COPD.

Subject (n)	933
Male/female (n)	844/89
Age (years)	66.8±8.4
Smoking status (%)
Non-smoker	16.3
Former smoker	64.0
Current smoker	19.7
Smoking history (pack-year)	40.4±26.3
Disease duration (years)	10.9±9.3
Proportion of GOLD grade (%)
I	6.1
II	29.8
III	44.3
IV	19.7

Data are presented as percentage of population or mean ± SD, unless otherwise stated. GOLD, Global Initiative for Chronic Obstructive Lung Disease.