Demographics at Time of Test and Pulmonary Function Results
| EP versus PTC | ||||
|---|---|---|---|---|
| Term controls (n = 95) | (n = 52) | (n = 41) | Δ (95% CI) EP–PTC | |
| Age (weeks)+ | 48.7 (14.2) | 58.2 (11.8) | 48.0 (6.8) | 10.3 (6.4; 14.1)*** |
| Weight z-score≠ | 0.5 (1.0) | −0.20 (1.3) | −0.003 (1.0) | −0.2 (−0.7; 0.3) |
| Length z-score≠ | 0.8 (1.1) | 0.11 (1.4) | 0.59 (1.2) | −0.5 (−1.0; 0.1) |
| BMI z-score | 0.03 (0.9) | −0.35 (1.1) | −0.45 (0.9) | 0.1 (−0.3; 0.5) |
| Ethnicity | ||||
| White mothers | 82 (86%) | 21 (40%) | 15 (37%) | 4% (−16%; 23%) |
| Black mothers1 | 10 (10%) | 22 (42%) | 14 (34%) | 8% (−12%; 27%) |
| Other2 | 3 (3%) | 9 (17%) | 12 (29%) | −12% (−29%; 5%) |
| Pulmonary function results | ||||
| 6FRCpleth, z-score3 | −0.13 (1.1) | −0.06 (1.8) | −0.52 (1.0) | 0.5 (−0.2; 1.1) |
| 7FEV0.5 z-score4 | 0.17 (0.9) | −1.62 (1.4) | −0.61 (1.4) | −1.0 (−1.6;−0.4)*** |
| 7FVC z-score4 | 0.15 (1.0) | −0.92 (1.1) | −0.17 (1.1) | −0.8 (−1.2; −0.3)*** |
| 7FEF25–75 z-score4 | 0.06 (1.0) | −1.8 (1.7) | −0.74 (1.4) | −1.1 (−1.7; −0.5)*** |
| 7FEV0.5/FVC z-score5 | −0.12 (0.8) | −0.89 (0.8) | −0.62 (0.9) | −0.3 (−0.6; 0.1) |
Data presented as mean (SD) or n (%).
Δ (95% CI) in bold font denotes significant differences in body size and pulmonary function results between the two preterm groups. Differences with respect to the fullterm group were assessed using ANOVA and are summarized in text.
EP, extremely preterm; PTC, preterm controls; BMI, body mass index.
Δ, mean difference between groups; +, age at time of test corrected for gestation; ≠, calculated using the UK-WHO algorithm.15
P ≤ 0.001 for t-tests between EP and PTC groups.
Including Afro-Caribbean and African mothers.
Includes infants born to mothers of mixed ethnic origins, Asian or Chinese mothers.
Calculated according to Nguyen et al.16
Calculated according to Lum et al.19
Calculated according to Jones et al.23
n = 41 for EP, 35 for PTC and 74 for term controls for FRCpleth.
n = 49 for EP, 41 for PTC and 89 for term controls for forced expiratory volumes and flows.