Characteristics of the total, hypoxic, and non-hypoxic study groups
| Characteristic | Total | Hypoxic | Non-hypoxic | Significance |
| Age (y) | 10.0 (SD 3.0) | 8.6 (SD 2.8) | 11.2 (SD2.8) | p = 0.02 |
| Median ΔHMP/ΔFEV1(%−1) | 0.042 | 0.021 | 0.073 | p = 0.0081 |
| Male sex | 16/27 | 8/12 | 8/15 | p = 0.48 |
| Length acute illness (h) | 62 (101) | 45 (44) | 76 (130) | p = 0.45 |
| Median chronic treatment score | 2 (1–4) | 2 (1–3) | 2 (1–4) | p = 0.27 |
| Median chronic severity score | 2 (1–4) | 2 (1–4) | 3 (1–4) | p = 0.71 |
| Self referral rate | 21/27 | 9/12 | 12/15 | p = 0.76 |
| Previous ICU/IV therapy | 2/26 | 2/11 | 0/15 | NS |