Percentages of “technician-accepted” maximal expiratory flow volume curves that meet the American Thoracic Society and/or European Respiratory Society acceptability and reproducibility criteria
| Criterion | Age | Total | |||
| <8 yrs | 8–11 yrs | 12–15 yrs | >15 yrs | ||
| Patients n | 36 | 175 | 146 | 89 | 446 |
| Vbe%FVC <5% | 77.2 | 80.6 | 91.7 | 96.5 | 91.5 |
| Vbe <0.15 L | 97.5 | 95.6 | 94.5 | 85.4 | 94.8 |
| Vbe <0.10 L | 77.8 | 61.7 | 59.6 | 50.6 | 60.1 |
| tPEF <0.1 s | 75.3 | 77.8 | 89.9 | 92.0 | 84.7 |
| FET >6 s | 8.6 | 13.3 | 15.6 | 36.0 | 15.3 |
| ΔFVC <200 mL | 100 | 99.5 | 94.5 | 95.5 | 97.1 |
| ΔFVC <100 mL | 91.7 | 85.7 | 74.7 | 70.8 | 79.8 |
| ΔFVC % <5% | 82.7 | 89.8 | 85.6 | 89.5 | 87.9 |
| ΔFEV1 <200 mL | 100 | 99.0 | 98.2 | 97.5 | 98.4 |
| ΔFEV1 <100 mL | 91.7 | 90.9 | 78.1 | 79.8 | 84.3 |
| ΔFEV1 % <5% | 91.4 | 85.7 | 87.2 | 88.5 | 87.2 |
Data are presented as percentages unless otherwise stated
Vbe%FVC: backward extrapolated volume as percentage of forced vital capacity
Vbe: backward extrapolated volume
tPEF: time to peak expiratory flow
FET: forced expiratory time
ΔFVC: absolute difference between two highest forced vital capacities
ΔFVC %: percentage difference between two highest forced vital capacities
ΔFEV1: absolute difference between two highest forced expiratory volumes in one second
ΔFEV1 %: percentage difference between two highest forced expiratory volumes in one second