Table 3

Baseline spirometry, reported as group mean Z-scores (mean), in healthy children and those with asthma measured on the first visit

Children with asthma (n=244)Healthy children (n=364)Difference (mean (95% CI))p Value
z-FVC−0.010.09−0.10 (−0.6 to 0.08)0.11
z-FEV1−0.440.25−0.69 (−0.98 to 0.27)0.008
z-FEV0.75−0.740.09−0.83 (−1.37 to 0.27)0.007
z-FEV0.5−0.550.06−0.61 (−1.41 to 0.34)0.007
z-FEF25–75−0.97−0.04−0.93 (−0.99 to 0.23)<0.001
z-FEF25−0.99−0.05−0.94 (−0.95 to 0.13)0.004
z-FEF50−0.89−0.01−0.88 (−0.92 to 0.28)<0.001
z-FEF75−0.83−0.01−0.82 (−0.89 to 0.18)0.005
z-PEF−0.250.02−0.23 (−0.30 to 0.01)0.12
  • The difference between groups (mean and 95% CIs) are also shown. Significance between groups was assessed using Student's t-tests.

  • Baseline spirometry on visit 1.

  • FEF, forced expiratory flow; PEF, peak expiratory flow.