Table 2

 Prevalence of spirometry-defined COPD by smoking status

COPDTotal(N = 8215)Never smokers(N = 3686)Ex-smokers(N = 2551)Smokers(N = 1978)
Data shown as % (N).
a,b,cDifferent letters indicate significant group differences (p<0.02).
Mild5.5 (455)4.9 (180)a5.5 (141)a,b6.8 (134)b
Moderate5.8 (480)3.1 (116)a7.1 (180)b9.3 (184)c
Severe/very severe1.9 (158)0.7 (26)a2.7 (68)b3.2 (64)b
Overall13.3 (1093)8.7 (322)a15.2 (389)b19.3 (382)c