Characteristics of the study population
| Number of acceptable manoeuvres | |||
|---|---|---|---|
| Characteristic | ≥3 (n=408) | 2 (n=195) | At least 2 (n=603) |
| FEV1, FEV0.5=forced expiratory volume in 1 or 0.5 seconds; FVC=forced vital capacity; PEF=peak expiratory flow. | |||
| Frequency distributions and means with 95% confidence intervals (95%CI) are given separately for children with at least three acceptable manoeuvres and those with two acceptable manoeuvres. | |||
| Age (years) | 4.7 (4.6 to 4.8) | 4.3 (4.1 to 4.4) | 4.5 (4.5 to 4.6) |
| Sex (%) | |||
| Boys | 51 | 56 | 52 |
| Girls | 49 | 44 | 48 |
| Height (cm) | 110.3 (109.6 to 111.0) | 106.8 (105.7 to 107.8) | 109.2 (108.6 to 109.8) |
| Weight (kg) | 18.5 (18.2 to 18.8) | 17.2 (16.7 to 17.7) | 18.1 (17.8 to 18.3) |
| FEV1 (l) | 1.15 (1.12 to 1.18) | 0.99 (0.95 to 1.03) | 1.10 (1.08 to 1.12) |
| FEV0.5 (l) | 0.98 (0.96 to 1.00) | 0.86 (0.85 to 0.89) | 0.94 (0.92 to 0.96) |
| FVC (l) | 1.20 (1.17 to 1.23) | 1.02 (0.98 to 1.06) | 1.15 (1.12 to 1.18) |
| PEF (l/s) | 2.83 (2.77 to 2.89) | 2.48 (2.39 to 2.57) | 2.71 (2.66 to 2.71) |