Mean and 95% CIs of baseline (before 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 | 289 | 0.18 (−0.55 to 0.91) | 258 | 0.21 (−0.62 to 1.05) | 304 | 0.28 (−0.47 to 1.02) | 235 | 0.47 (−0.34 to 1.28) | 328 | −0.01 (−0.07 to 0.06) | |
| Yes | 137 | −0.38 (−1.33 to 0.56) | 124 | −0.44 (−1.55 to 0.67) | 149 | −0.57 (−1.65 to 0.51) | 115 | −0.97 (−2.12 to 0.18) | 160 | −0.08 (−0.15 to −0.01) | |
| p Value | 0.37 | 0.37 | 0.20 | 0.04 | 0.02 | ||||||
| Active smoking, 16–26 years | |||||||||||
| No | 279 | −0.04 (−0.74 to 0.67) | 255 | −0.15 (−0.97 to 0.67) | 300 | 0.16 (−0.58 to 0.90) | 230 | 0.39 (−0.44 to 1.22) | 321 | 0.02 (−0.04 to 0.08) | |
| Yes | 147 | 0.07 (−0.94 to 1.08) | 127 | 0.30 (−0.86,1.46) | 153 | −0.31 (−1.41 to 0.78) | 120 | −0.74 (−1.84 to 0.35) | 167 | −0.13 (−0.23 to −0.04) | |
| p Value | 0.86 | 0.54 | 0.47 | 0.11 | 0.001 | ||||||
| Combined smoking groups | |||||||||||
| Parental | Active, 16–26 years | ||||||||||
| No | No | 203 | 0.15 (−0.70 to 1.00) | 188 | −0.07 (−1.06 to 0.92) | 220 | 0.28 (−0.58 to 1.14) | 169 | 0.49 (−0.51 to 1.48) | 233 | 0.03 (−0.04 to 0.10) |
| No | Yes | 86 | 0.26 (−1.18 to 1.69) | 70 | 0.97 (−0.62 to 2.57) | 84 | 0.29 (−1.24 to 1.81) | 66 | 0.45 (−0.97 to 1.86) | 95 | −0.10 (−0.25 to 0.04) |
| Yes | No | 76 | −0.54 (−1.84 to 0.76) | 67 | −0.36 (−1.86 to 1.13) | 80 | −0.16 (−1.66 to 1.34) | 61 | 0.12 (−1.44 to 1.68) | 88 | −0.01 (−0.10 to 0.08) |
| Yes | Yes | 61 | −0.19 (−1.60 to 1.22) | 57 | −0.53 (−2.25 to 1.19) | 69 | −1.04 (−2.64 to 0.55) | 54 | −2.20 (−3.89 to −0.51) | 72 | −0.18 (−0.29 to −0.06) |
| p Value | 0.82 | 0.56 | 0.52 | 0.047 | 0.002 | ||||||
YR11, age 11 years; YR16, age 16 years; YR22 age 22 years; YR26, age 26 years.