Table 5—

Cut-off points for acceptability and reproducibility criteria for values which can be achieved by 90% of the study population

CriterionAgeTotal
<8 yrs8–11 yrs12–15 yrs>15 yrs
Patients n3617514689446
Vbe%FVC %6.45.84.64.25.4
Vbe L0.110.120.120.160.13
tPEF s0.110.120.100.090.11
FET s1.32.11.82.11.8
ΔFVC mL83101159150127
ΔFVC %5.04.95.64.75.3
ΔFEV1 mL6092128136110
ΔFEV1 %4.76.36.75.46.2
  • 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