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Table 1 Patient characteristics

From: Smoking cessation and bronchial epithelial remodelling in COPD: a cross-sectional study

  COPD Current smokers COPD Ex-smokers
   combined group quit < 3.5 yrs quit ≥3.5 yrs
General     
Sex (M/F, n) 59/13 40/2 * 20/1 20/1
Age (yrs) 60 ± 8 64 ± 7 * 61 ± 8 67 ± 4 *†
Pack-years (yrs) 43 (32–56) 37 (28–53) 45 (29–65) 35 (26–41) *
Duration of smoking cessation (yrs) - 3.5 (1–10) 1.0 (1.0–2.0) 10 (6.5–14.5)
Smoking duration (yrs) 44 ± 8 41 ± 10 43 ± 11 39 ± 8
Chronic bronchitis (%) 55.6 31.0 * 23.8 * 38.1
Lung Function     
Postbronchodilator FEV1 (%pred) 63.3 ± 8.3 62.5 ± 9.6 62.6 ± 10 62.5 ± 9.4
Postbronchodilator FEV1/IVC (%) 49.5 ± 8.5 46.0 ± 8.3 * 45.3 ± 8.6 * 46.7 ± 8.1
ΔFEV1 (%pred) 6.9 ± 5.2 6.8 ± 4.5 6.9 ± 3.9 6.8 ± 5.1
KCO (%pred) 73.3 ± 25.1 80.4 ± 25.9 75.3 ± 24.9 85.7 ± 26.5 *
  1. Data are presented as mean ± standard deviation or median (IQR: 25th – 75th percentile), ex-smokers are divided in two groups based on median duration of smoking cessation (3.5 years). FEV1 = Forced expiratory volume in one second, IVC = Inspiratory vital capacity, ΔFEV1 = Reversibility to salbutamol (change in FEV1 as percentage of predicted), KCO = Diffusing capacity for carbon monoxide per liter alveolar volume, pred = predicted. Patient characteristics have been described before [17].
  2. * p < 0.05: compared to COPD smokers [Chi-square tests for sex differences, 2-tailed unpaired t-tests for other (log-transformed) data]; † p < 0.05: compared to COPD ex-smokers who quit <3.5 yrs (2-tailed unpaired t-tests)