Spirometry variables at 8 and 18 years within the preterm group comparing those with and without BPD in the newborn period
| 8 years | 18 years | |||||
|---|---|---|---|---|---|---|
| Variable | BPD n=89 | No BPD n=151 | Mean difference (95% CI), p value | BPD n=77 | No BPD n=132 | Mean difference (95% CI), p value |
| FEV1 | ||||||
| z-score | −1.23 (1.14) | −0.76 (0.98) | −0.47 (−0.75 to −0.20), 0.001 | −1.46 (1.14) | −0.77 (0.96)* | −0.68 (−0.98 to −0.39), <0.001 |
| % predicted | 85.3 (13.9) | 90.9 (11.7) | −5.7 (−9.2 to −2.2), 0.001 | 82.7 (13.7) | 90.9 (11.4)* | −8.1 (−11.6 to 4.7), <0.001 |
| FVC | ||||||
| z-score | −1.16 (1.31) | −0.72 (1.10) | −0.39 (−0.70 to −0.08), 0.014 | −0.68 (1.14) | −0.36 (0.95) | −0.32 (−0.61 to −0.029), 0.030 |
| % predicted | 86.4 (15.5) | 91.5 (13.0) | −5.1 (−8.8 to −1.5), 0.006 | 92.1 (13.3) | 95.8 (11.2) | −3.6 (−7.0 to −0.2), 0.036 |
| FEV1/FVC | ||||||
| z-score | 0.03 (1.56) | 0.14 (1.49) | −0.11 (−0.50 to 0.29), 0.60 | −1.17 (1.35) | −0.67 (1.15)* | −0.51 (−0.85 to −0.16), 0.004 |
| % | 87.9 (9.4) | 88.7 (9.0) | −0.8 (−3.2 to 1.6), 0.52 | 78.6 (10.6) | 83.3 (8.4)* | −4.6 (−7.3 to −2.0), <0.001 |
| FEF25%–75% | ||||||
| z-score | −1.56 (1.09)† | −1.22 (1.09)‡ | −0.34 (−0.63 to −0.05), 0.021 | −1.79 (1.23) | −1.12 (1.10) | −0.67 (−0.99 to −0.34), <0.001 |
| % predicted | 67.0 (22.6)† | 74.0 (23.4)‡ | −7.0 (−13.2 to −0.8), 0.026 | 65.3 (22.6) | 77.7 (21.9) | −12.4 (−18.7 to −6.2), <0.001 |
| FEF75% | ||||||
| z-score | −0.83 (1.15)§ | −0.49 (1.15)¶ | −0.34 (−0.66 to −0.02), 0.035 | −1.35 (1.17) | −0.71 (1.06)* | −0.64 (−0.95 to −0.33), <0.001 |
| % predicted | 79.1 (33.0)§ | 89.1 (37.0)¶ | −10.0 (−19.8 to −0.1), 0.047 | 66.4 (28.6) | 82.3 (30.6)* | −15.9 (−24.4 to −7.5), <0.001 |
*n=1 missing data.
†n=2 missing data.
‡n=5 missing data.
§n=10 missing data.
¶n=9 missing data.
BPD, bronchopulmonary dysplasia; FEF25%–75%, forced expiratory flow at 25%–75% of FVC; FEF75%, forced expiratory flow at 75% of FVC expired.