Table 5

Changes over time for spirometric z-scores from linear mixed models within the preterm group, contrasting BPD and no BPD groups

Change between 8 and 18 years
VariableBPDNo BPDInteraction
 zFEV1 −0.27 (−0.47 to −0.06) p=0.012−0.04 (−0.16 to 0.09) p=0.58−0.22 (−0.44 to −0.01) p=0.044
 zFVC0.50 (0.25 to 0.75) p<0.0010.33 (0.17 to 0.49) p<0.0010.15 (−0.12 to 0.42) p=0.28
 zFEV1/FVC−1.29 (−1.66 to −0.92) p<0.001−0.74 (−0.97 to −0.51) p<0.001−0.47 (−0.86 to −0.09) p=0.016
 zFEF25%–75% −0.31 (−0.53 to −0.09) p=0.0060.06 (−0.10 to 0.22) p=0.44−0.36 (−0.61 to −0.10) p=0.006
 zFEF75% −0.56 (−0.83 to −0.29) p<0.001−0.19 (−0.38 to −0.00) p=0.049−0.34 (−0.64 to −0.03) p=0.029
  • Values are mean difference (95% CI), unless otherwise stated.

  • BPD, bronchopulmonary dysplasia; FEF25%–75%, forced expiratory flow at 25%–75% of FVC; FEF75%, forced expiratory flow at 75% of FVC expired.