| 1982-85: Age: 18 years | 1991-92: Age: 18 years | 1999-00: Age: 19 years | P-value | |
| Z-FEV1: Term born | -0.00 (-0.28, 0.27) n= 46 | -0.26 (-0.64, 0.11) n=28 | -0.12 (-0.44, 0.20) n= 37 | 0,51 |
| Z-FEV1: EP-born: without BPD | -1.10 (- 1.64, -0.55) n= 34 | -0.63 (-1.02, - 0.24) n=19 | -0.64 (-1.08,-0.19) n= 20 | 0,29 |
| Z-FEV1: EP born: with BPD | -1,62 (-2.22, -1.03) n=12 | -1.45 (-1.91, -0.98) n=12 | -0.50 (-0.93, -0.07) n = 21 | <0.01 |
The table shows FEV1 z-score group means (95% confidence interval)