Table 3

Spirometric lung function data comparing term-born with extremely preterm subjects (n=286 subjects)

82–85 cohort*91–92 cohort99–00 cohort
Age (mean, range)17.7 (15.3–19.9)24.9 (22.5–27.0)34.5 (32.1–37.6)10.6 (9.7–11.5)17.8 (17.0–19.2)27.1 (26.1–28.4)11.6 (10.1–13.8)19.8 (18.2–21.4)
n/eligble
Term-born46/4640/4634/4635/3528/3526/3454/5743/57
EP no BPD34/3832–33/3825–26/3623/2319/2315/2326/4327/43
EP BPD12/1312/139–10/1212/1212/129/1232/4523/45
Mean95% CIP valueMean95% CIP valueMean95% CIP valueMean95% CIP valueMean95% CIP valueMean95% CIP valueMean95% CIP valueMean95% CIP value
FEV1 z-score
Term-born (ref)0.0−0.3 to 0.3−0.1−0.4 to 0.20.1−0.2 to 0.4−0.1−0.4 to 0.3−0.2−0.6 to 0.10.1−0.2 to 0.5−0.3−0.6 to −0.1−0.1−0.4 to 0.2
EP no BPD−1.1−1.5 to −0.8<0.001−0.9−1.2 to −0.6<0.001−0.9−1.2 to −0.5<0.001−0.6−1.0 to −0.10.07−0.6−1.1 to −0.20.17−0.4−0.8 to 0.10.08−0.6−0.9 to −0.20.33−0.5−0.9 to −0.20.07
EP BPD−1.5−2.1 to −1.0<0.001−1.4−1.9 to −0.8<0.001−1.6−2.2 to −1.0<0.001−1.5−2.1 to −0.9<0.001−1.4−2.0 to −0.9<0.001−1.5−2.1 to −0.9<0.001−0.7−1.1 to −0.40.08−0.6−1.0 to −0.30.03
FVC z-score
Term-born (ref)−0.2−0.5 to 0.10.0−0.3 to 0.30.2−0.2 to 0.5−0.1−0.5 to 0.2−0.2−0.6 to 0.20.40.1 to 0.8−0.2−0.4 to 0.10.0−0.3 to 0.3
EP no BPD−0.9−1.3 to −0.60.003−0.4−0.7 to 0.00.11−0.3−0.7 to 0.00.05−0.5−1.0 to −0.10.17−0.4−0.9 to 0.00.41−0.1−0.5 to 0.40.07−0.1−0.5 to 0.30.67−0.1−0.5 to 0.30.66
EP BPD−1.1−1.6 to −0.50.01−0.6−1.2 to 0.00.07−0.9−1.5 to −0.30.002−0.7−1.2 to −0.10.15−0.2−0.8 to 0.40.95−0.1−0.7 to 0.50.12−0.2−0.5 to 0.20.96−0.3−0.7 to 0.10.20
FEV1/FVC z-score
Term-born (ref)0.40.1 to 0.6−0.2−0.4 to 0.1−0.2−0.5 to 0.10.1−0.2 to 0.4−0.1−0.5 to 0.2−0.5−0.9 to −0.2−0.3−0.6 to 0.0−0.2−0.5 to 0.0
EP no BPD−0.3−0.7 to 0.00.002−0.9−1.3 to −0.6<0.001−0.9−1.3 to −0.50.0040.0−0.4 to 0.40.73−0.3−0.7 to 0.20.55−0.5−1.0 to −0.10.96−0.8−1.2 to −0.40.03−0.7−1.1 to −0.30.06
EP BPD−0.7−1.2 to −0.10.001−1.0−1.6 to −0.50.007−1.2−1.8 to −0.60.003−1.4−2.0 to −0.8<0.001−1.7−2.3 to −1.2<0.001−1.9−2.5 to −1.3<0.001−0.9−1.2 to −0.60.008−0.5−0.9 to −0.10.30
FEF25–75%z-score
Term-born (ref)0.2−0.1 to 0.5−0.1−0.4 to 0.2−0.1−0.4 to 0.2−0.2−0.6 to 0.1−0.3−0.7 to 0.0−0.4−0.8 to −0.1−0.6−0.8 to −0.3−0.3−0.5 to 0.0
EP no BPD−1.0−1.3 to −0.7<0.001−1.2−1.6 to −0.9<0.001−1.1−1.5 to −0.8<0.001−0.8−1.2 to −0.40.05−0.6−1.0 to −0.20.32−0.7−1.1 to −0.20.35−1.0−1.3 to −0.60.06−0.8−1.2 to −0.40.02
EP BPD−1.5−2.0 to −0.9<0.001−1.5−2.0 to −0.9<0.001−1.6−2.2 to −1.1<0.001−1.9−2.5 to −1.4<0.001−1.9−2.5 to −1.4<0.001−2.1−2.7 to −1.5<0.001−1.2−1.6 to −0.90.003−0.9−1.3 to −0.50.007
  • All results are based on longitudinal mixed-effects models. The p values compare EP subjects with controls.

  • *Two of the eligible non-participants could not be classified according to BPD status, but are presented in the non-BPD group.

  • BPD, bronchopulmonary dysplasia (supplemental oxygen or respiratory support at postmenstrual age ≥36 weeks); EP, subjects born extremely preterm or with extremely low birth weight (gestational age ≤28 weeks or birth weight ≤1000 g); FEF25–75%, forced expiratory flow at 25%–75% of FVC; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; ref, reference level.