The association between ΔIC (%) and clinical indices
| ΔIC20 % | ΔIC30 % | ΔIC40 % | |
| ACT | r=−0.24, p=0.09 | r=−0.34, p=0.02 | r=−0.28, p=0.05 |
| FEV1 % predicted | r=−0.37, p=0.008 | r=−0.51, p=0.0001 | r=−0.56, p<0.0001 |
| Blood eosinophil % | r=0.05, p=0.72 | r=0.12, p=0.90 | r=0.02, p=0.91 |
| Serum periostin ng·mL−1 | r=0.37, p=0.008 | r=0.43, p=0.002 | r=0.41, p=0.003 |
| FeNO ppb | r=0.003, p=0.98 | r=0.11, p=0.45 | r=0.22, p=0.12 |
ACT: asthma control test; FEV1: forced expiratory volume in 1 s; FeNO: fractional exhaled nitric oxide; ΔIC: the reduction percentage of inspiratory capacity from baseline (ICrest) for each breathing frequency (ΔIC20, ΔIC30 and ΔIC40).