Table 1 Clinical characteristics
Non-smokers without emphysema (NE-NS)(n-11)Smokers without emphysema (NE-S)(n = 9)Patients with severe emphysema (SE)(n = 10)Between group differences (p value)
Median (range) age (years)58 (32–72)58.5 (30–68)57.5 (49–65)0.99
Sex ratio (F/M)2/90/91/90.28
Median (range) no of packs smoked037.5 (10–50)‡52 (20–100)†‡10−4
Time since smoking cessation (years)NA0 (0–20)1 (0–8)0.88
Current smokers/ex-smokersNA7/22/810−4
  • †p = 10−3 vs NE-S; ‡p = 10−4 vs NE-NS as assessed by the Mann-Whitney U-test. NA, not applicable.