Mean and SD of z-scores of lung function measures adjusted for age, gender and height at age 8–9 and 14–17 years, with CIs for the difference of means (14–17 − 8–9 years of age), unadjusted and adjusted for maternal smoking in pregnancy and social status
| 25–32 weeks: age 8–9 (n=30) | 25–32 weeks: age 14–17 (n=30) | Difference (95% CI) (unadjusted) | Difference (95% CI) (adjusted) | p Value for adjusted analysis | |||
| Mean | SD | Mean | SD | ||||
| FEV1 | −0.441 | 0.946 | −0.318 | 0.932 | 0.123 (−0.258 to 0.504) | 0.013 (−0.471 to 0.497) | 0.958 |
| FVC | −0.032 | 1.050 | −0.052 | 0.918 | −0.021 (−0.408 to 0.367) | −0.275 (−0.764 to 0.214) | 0.271 |
| FEF25–75 | −0.717 | 0.944 | −0.572 | 0.909 | 0.145 (−0.202 to 0.491) | 0.227 (−0.214 to 0.688) | 0.313 |
| FEV1/FVC | −0.605 | 1.294 | −0.438 | 1.132 | 0.167 (−0.211 to 0.546) | 0.397 (−0.082 to 0.877) | 0.104 |
| FEF25–75/FVC | −0.665 | 0.941 | −0.509 | 0.949 | 0.156 (−0.184 to 0.496) | 0.296 (−0.134 to 0.727) | 0.177 |
| 33–34 weeks: age 8–9 (n=42) | 33–34 weeks: age 14–17 (n=42) | Difference (95% CI) (unadjusted) | Difference (95% CI) (adjusted) | p Value for adjusted analysis | |||
| Mean | SD | Mean | SD | ||||
| FEV1 | −0.483 | 1.039 | −0.079 | 1.191 | 0.404 (0.082 to 0.726) | 0.347 (0.015 to 0.680) | 0.041 |
| FVC | −0.090 | 0.938 | 0.130 | 0.960 | 0.220 (−0.108 to 0.547) | 0.226 (−0.562 to 0.111) | 0.188 |
| FEF25–75 | −0.622 | 1.127 | −0.336 | 1.173 | 0.287 (−0.006 to 0.580) | 0.241 (−0.062 to 0.544) | 0.119 |
| FEV1/FVC | −0.621 | 1.272 | −0.432 | 1.156 | 0.190 (−0.130 to 0.510) | 0.143 (−0.187 to 0.473) | 0.395 |
| FEF25–75/FVC | −0.566 | 1.052 | −0.445 | 1.017 | 0.121 (−0.166 to 0.408) | 0.112 (−0.183 to 0.408) | 0.456 |
| 35–36 weeks: age 8–9 (n=107) | 35–36 weeks: age 14–17 (n=107) | Difference (95% CI) (unadjusted | Difference (95% CI) (adjusted) | p Value for adjusted analysis | |||
| Mean | SD | Mean | SD | ||||
| FEV1 | 0.148 | 0.863 | 0.021 | 0.860 | −0.127 (−0.332 to 0.079) | −0.130 (−0.343 to 0.084) | 0.234 |
| FVC | 0.115 | 0.941 | 0.045 | 0.955 | −0.070 (−0.275 to 0.135) | −0.097 (−0.308 to 0.115) | 0.370 |
| FEF25–75 | 0.086 | 0.900 | −0.076 | 0.888 | −0.161 (−0.345 to 0.022) | −0.132 (−0.322 to 0.059) | 0.175 |
| FEV1/FVC | 0.006 | 0.911 | −0.048 | 1.076 | −0.054 (−0.258 to 0.150) | −0.007 (−0.218 to 0.205) | 0.951 |
| FEF25–75/FVC | 0.027 | 0.970 | −0.104 | 0.992 | −0.131 (−0.311 to 0.049) | −0.095 (−0.281 to 0.091) | 0.318 |
| Term weeks: age 8–9 (n=3431) | Term weeks: age 14–17 (n=3431) | Difference (95% CI) (unadjusted) | Difference (95% CI) (adjusted) | p Value for adjusted analysis | |||
| Mean | SD | Mean | SD | ||||
| FEV1 | −0.004 | 1.006 | 0.010 | 1.002 | 0.014 (−0.021 to 0.051) | −0.013 (−0.060 to 0.034) | 0.582 |
| FVC | −0.019 | 1.003 | 0.005 | 1.001 | 0.025 (−0.012 to 0.061) | 0.007 (−0.054 to 0.040) | 0.774 |
| FEF25–75 | 0.014 | 0.997 | 0.010 | 1.001 | −0.005 (−0.037 to 0.028) | −0.016 (−0.058 to 0.027) | 0.468 |
| FEV1/FVC | 0.016 | 1.003 | 0.003 | 0.982 | −0.013 (0.049 to 0.023) | −0.006 (−0.053 to 0.041) | 0.801 |
| FEF25–75/FVC | 0.023 | 1.005 | 0.005 | 0.989 | −0.017 (−0.049 to −0.014) | −0.011 (−0.052 to −0.031) | 0.616 |
FEF25–75, forced expiratory volume at 25–75% of FVC; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.