| Healthy controls | Asthmatic patients at first visit baseline | p Value | |
| Number | 29 (28 for Scond and Sacin) | 31 | |
| Mean (range) age (years) | 11.1 (5–16) | 10.6 (5–15) | 0.54 |
| Sex (M/F) | 18/11 | 17/14 | |
| Medication at time of testing | |||
| ICS | – | 6% | |
| ICS+LABA | – | 52% | |
| ICS+montelukast | – | 42% | |
| Atopy | |||
| Positive skin prick testing to aeroallergen | – | 58% | |
| Eczema | – | 16% | |
| Hay fever | – | 71% | |
| Mean (range) height (cm) | 148 (118–180) | 144 (110–186) | 0.38 |
| Median (range) Feno (ppb) | 18 (3–50) | 14 (5–300) | 0.63* |
| Mean (SD) FEV1 z-score | −0.69 (0.88) | −1.09 (1.28) | 0.16 |
| Range | −2.64–1.28 | −4.00–1.82 | |
| Mean (SD) LCI (CEV/FRC) | 6.24 (0.47) | 6.69 (0.91) | 0.02 |
| Range | 5.14–7.05 | 5.49–9.46 | |
| Mean (SD) Scond, Vt corrected | 0.017 (0.02) | 0.026 (0.02) | 0.06 |
| Range | −0.03–0.06 | −0.01–0.09 | |
| Mean (SD) Sacin, Vt corrected | 0.12 (0.06) | 0.14 (0.02) | 0.23 |
| Range | 0.02–0.29 | 0.05–0.40 | |
| Mean (SD) Vt (l) | 0.55 (0.24) | 0.45 (0.17) | 0.07 |
| Range | 0.19–0.99 | 0.23–0.80 | |
| Mean (SD) FRC (l) | 2.14 (1.02) | 1.91 (0.78) | 0.31 |
| Range | 0.80–4.51 | 0.85–3.82 | |
| Mean (SD) Vd/Vt ratio | 0.27 (0.06) | 0.27 (0.05) | 0.89 |
| Range | 0.13–0.37 | 0.17–0.36 |
Comparison of groups at baseline.
CEV, cumulative expired volume; Feno, fraction of expired nitric oxide; FEV1, forced expiratory volume in 1 s; FRC, functional residual capacity; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LCI, lung clearance index; Sacin, Scond, phase III (alveolar) slope of the acinar and conductive airways, respectively; Vd, dead space; Vt, tidal volume.
*Mann-Whitney non-parametric test.