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Table 3 Comparison of e-Cigarette and conventional cigarette users (dual users) vs e-Cigarette only users (single users) at 12- and 24-month follow-up visits

From: Evidence for harm reduction in COPD smokers who switch to electronic cigarettes

Parameter Baseline 12-Month Follow-up 24-Month Follow-up
COPD EC users reducing cig use (dual users) (n = 11) (n = 11) (n = 11)
 Sex 10 M, 1 F 10 M, 1 F 11 M
 % Smoking reduction compared to baseline - 82.6 (±4.8) 85.1 (±4.7)
 post-BD FEV1a (L) 1.23 (0.94, 1.6) 1.20 (0.91, 1.70) 1.28 (0.92, 1.96)
 post-BD FVCa (L) 2.34 (2.04, 2.86) 2.35 (2.07, 2.89) 2.57 (2.22, 2.93)
 %FEV/FVCa 50.9 (47, 61.2) 51.2 (46.9, 64) 51.8 (43.3, 65.7)
 Cig/dayb 23.7 (±5.4) 4 (±1.2) 3.5 (±1.3)
 CAT scorea 25 (19.5, 26.5) 20 (18, 22) 18 (15, 22)
 COPD Exacerbationsb 2.6 (±0.8) 2.3 (±0.8) 1.5 (±0.8)
COPD EC users ceasing cig use (single users) (n = 13) (n = 13) (n = 13)
 Sex 10 M, 3 F 10 M, 3 F 9 M, 3 F
 Smoking reduction compared to baseline - - -
 post-BD FEV1a (L) 1.32 (0.96, 1.76) 1.26 (0.94, 1.72) 1.3 (0.95, 1.63)
 post-BD FVCa (L) 2.57 (2.01, 2.65) 2.57 (1.92, 2.72) 2.44 (1.72, 2.82)
 %FEV/FVCa 61.9 (50.8, 66.4) 61.5 (50.6, 65.6) 61.5 (50, 65.2)
 Cig/dayb 20.2 (±2.7) - -
 CAT scorea 20 (17, 24) 16 (14, 18) 17 (15, 20)
 COPD Exacerbationsb 2.07 (±1.0) 1.3 (±1) 1.4 (±1)
  1. Abbreviations: n number, COPD Chronic obstructive pulmonary disease, EC e-Cigarette, M male, F female, BD bronchodilator, L litre, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, cig conventional cigarettes, CAT COPD assessment tool
  2. aMedian (interquartile range); b Mean (± standard deviation)