Table 2 Associations between electronic cigarette use and asthma symptoms according to cigarette smoking status
| Â | Current wheeze | Current asthma | Current uncontrolled asthma symptoms | |||
|---|---|---|---|---|---|---|
Cigarette and e-cigarette use | % (n/total) | aPR* (95% CI) | % (n/total) | aPR* (95% CI) | % (n/total) | aPR* (95% CI) |
Never cigarette smoker | ||||||
 Never e-cigarette use | 21.2 (141/665) | 1.00 (Reference) | 13.4 (89/665) | 1.00 (Reference) | 11.7 (78/665) | 1.00 (Reference) |
 Former e-cigarette use | 30.2 (13/43) | 1.30 (0.75–2.23) | 16.3 (7/43) | 1.43 (0.70–2.92) | 14.0 (6/43) | 1.34 (0.63–2.86) |
 Current e-cigarette use | 31.4 (11/35) | 1.54 (1.01–2.45) | 25.7 (9/35) | 1.85 (1.03–3.41) | 22.9 (8/35) | 1.56 (0.80–3.06) |
Former cigarette smoker | ||||||
 Never e-cigarette use | 27.2 (28/103) | 1.26 (0.89–1.80) | 22.3 (23/103) | 1.67 (1.08–2.58) | 17.5 (18/103) | 1.42 (0.88–2.32) |
 Former e-cigarette use | 27.5 (19/69) | 1.24 (0.81–1.92) | 14.5 (10/69) | 1.11 (0.58–2.11) | 14.5 (10/69) | 1.18 (0.63–2.23) |
 Current e-cigarette use | 33.3 (24/72) | 1.52 (1.05–2.21) | 20.8 (15/72) | 1.71 (1.05–2.78) | 27.8 (20/72) | 2.28 (1.45–3.58) |
Current cigarette smoker | ||||||
 Never e-cigarette use | 36.4 (16/44) | 1.64 (1.06–2.55) | 20.5 (9/44) | 1.73 (1.01–3.21) | 13.6 (6/44) | 1.01 (0.43–2.38) |
 Former e-cigarette use | 36.7 (18/49) | 1.57 (1.02–2.43) | 22.5 (11/49) | 1.89 (1.05–3.43) | 26.5 (13/49) | 2.34 (1.38–3.99) |
 Current e-cigarette use | 41.9 (111/265) | 1.87 (1.44–2.42) | 26.0 (69/265) | 1.92 (1.33–2.76) | 24.9 (66/265) | 1.97 (1.35–2.88) |