Mean and 95% CIs of post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) residuals at age 11, 16, 22 and 26 years and of their linear trends between age 11 and 26 years across parental and active smoking groups
| FEV1/FVC residuals YR11 | FEV1/FVC residuals YR16 | FEV1/FVC residuals YR22 | FEV1/FVC residuals YR26 | Linear trends of FEV1/FVC residuals per year from YR11 to YR26 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| N | Mean (95% CI) | N | Mean (95% CI) | N | Mean (95% CI) | N | Mean (95% CI) | N | Mean (95% CI) | ||
| Parental smoking | |||||||||||
| No | 278 | 0.37 (−0.25 to 1.00) | 255 | 0.06 (−0.64 to 0.76) | 302 | 0.36 (−0.26 to 0.98) | 225 | 0.36 (−0.36 to 1.09) | 321 | −0.01 (−0.08 to 0.06) | |
| Yes | 133 | −0.77 (−1.65 to 0.11) | 121 | −0.13 (1.08 to 0.82) | 147 | −0.73 (−1.61 to 0.15) | 115 | −0.71 (−1.66 to 0.24) | 156 | −0.08 (−0.14 to −0.01) | |
| p Value | 0.04 | 0.75 | 0.049 | 0.08 | 0.18 | ||||||
| Active smoking, 16–26 years | |||||||||||
| No | 267 | −0.07 (−0.69 to 0.56) | 250 | −0.13 (−0.82 to 0.56) | 298 | 0.12 (−0.49 to 0.74) | 224 | 0.31 (−0.41 to 1.04) | 314 | −0.01 (−0.07 to 0.06) | |
| Yes | 144 | 0.12 (−0.75 to 0.99) | 126 | 0.26 (−0.71 to 1.23) | 151 | −0.24 (−1.15 to 0.66) | 116 | −0.61 (−1.56 to 0.35) | 163 | −0.07 (−0.16 to 0.02) | |
| p Value | 0.72 | 0.52 | 0.50 | 0.14 | 0.054 | ||||||
| Combined smoking groups | |||||||||||
| Parental | Active, 16–26 years | ||||||||||
| No | No | 195 | 0.31 (−0.42 to 1.03) | 185 | −0.12 (−0.95 to 0.71) | 219 | 0.41 (−0.31,1.13) | 163 | 0.41 (−0.47 to 1.29) | 229 | −0.00 (−0.09 to 0.08) |
| No | Yes | 83 | 0.50 (−0.67 to 1.67) | 70 | 0.54 (−0.78 to 1.86) | 83 | 0.22 (−1.02 to 1.46) | 62 | 0.24 (−1.03 to 1.51) | 92 | −0.02 (−0.14 to 0.11) |
| Yes | No | 72 | −1.08 (−2.29 to 0.12) | 65 | −0.17 (−1.44 to 1.11) | 79 | −0.66 (−1.84 to 0.52) | 61 | 0.06 (−1.20 to 1.31) | 85 | −0.02 (−0.11 to 0.06) |
| Yes | Yes | 61 | −0.39 (−1.72 to 0.94) | 56 | −0.10 (−1.56 to 1.37) | 68 | −0.81 (−2.17 to 0.55) | 54 | −1.58(−3.02 to −0.13) | 71 | −0.14 (−0.25 to −0.03) |
| p Value | 0.18 | 0.84 | 0.26 | 0.13 | 0.16 | ||||||
YR11, age 11 years; YR16, age 16 years; YR22 age 22 years; YR26, age 26 years.