FIG. 2.

Mean FEV₁ values (expressed as percent of its value at the age of 25) by age, for healthy never smokers (NS) and continuous smokers (CS). Data for (A) males and (B) females. The mean FEV₁ decline value (and 95% CIs) for males was 38.2 mL (33.9-42.6) and for females 23.9 mL (20.9-27.0), with a p value <0.001. *p < 0.05 vs. healthy NS. (From Kohansal et al.³² Reprinted with permission of the American Thoracic Society.)