Age group breakdown and data completeness
| Age | Under 1 | 1–2 years | 2–5 years | 5–12 years | 12–16 years | |
| Frequency (n (%))* | 2072 (13.7) | 1261 (8.3) | 3045 (20.1) | 4572 (30.21) | 4183 (27.6) | N=15 133 (100%) |
| Complete prehospital physiology (n (%)) | 145 (2.9) | 59 (1.2) | 445 (9.0) | 1915 (38.6) | 2398 (48.3) | N=4962 (32.8%) |
| Complete first available physiology (n (%))† | 508 (24.5) | 260 (20.6) | 1093 (35.9) | 3095 (67.7) | 3299 (78.9) | N=8255 (54.5%) |
| Complete first available physiology (n (%))‡ | 1178 (56.7) | 675 (53.5) | 2044 (67.1) | 3755 (82.1) | 3631 (86.8) | N=11 283 (74.6%) |
*Overall study population age <16 years, n=15 133.
†Complete first available physiological data (ED and prehospital physiological data).
‡Complete first available physiological data (ED and prehospital physiological) using imputed data.