Association between significant clinical variables and primary outcome
| Finding | Total (%) (n = 22 772) | Negative for clinically significant intracranial pathology (n = 22 491) | Positive for clinically significant intracranial pathology (n = 281) | p Value | Positive predictive value |
|---|---|---|---|---|---|
| GCS, Glasgow Coma Score; LOC, loss of consciousness; NAI, non-accidental injury; RTA, road traffic accident. | |||||
| History | |||||
| LOC>5 min | 213 (0.9) | 118 (0.5) | 95 (34) | <0.001 | 0.45 |
| Amnesia>5 min | 288 (1.3) | 226 (1.0) | 62 (22) | <0.001 | 0.22 |
| Drowsiness | 949 (4.2) | 889 (4.0) | 60 (21) | <0.001 | 0.063 |
| Vomiting ⩾3 times | 857 (3.8) | 801 (3.6) | 56 (20) | <0.001 | 0.065 |
| Suspicion of NAI | 61 (0.3) | 41 (0.2) | 20 (7.1) | <0.001 | 0.33 |
| Seizure after head injury (in patients without epilepsy) | 96 (0.4) | 68 (0.3) | 28 (10) | <0.001 | 0.29 |
| Examination | |||||
| GCS <14 | 266 (1.2) | 137 (0.6) | 129 (46) | <0.001 | 0.48 |
| GCS <15 if age <1 year | 79(0.3) | 71 (0.3) | 8(2.8) | <0.001 | 0.10 |
| Penetrating or depressed skull injury suspected or tense fontanelle | 104 (0.5) | 58 (0.3) | 46 (16) | <0.001 | 0.44 |
| Base of skull fracture suspected | 536 (2.4) | 451 (2.0) | 85(30) | <0.001 | 0.16 |
| Positive focal neurology | 150 (0.7) | 96 (0.4) | 54 (19) | <0.001 | 0.36 |
| Presence of bruise/swelling or laceration >5 cm in children aged <1 year | 52 (0.2) | 46 (0.2) | 6 (2.1) | <0.001 | 0.12 |
| Mechanism | |||||
| High-speed RTA | 204 (0.9) | 117 (0.5) | 87 (31) | <0.001 | 0.43 |
| Fall >3 m | 129 (0.6) | 103 (0.5) | 26 (9.3) | <0.001 | 0.20 |
| High-speed injury from projectile or object | 456 (2.0) | 438(1.9) | 18 (6.4) | <0.001 | 0.039 |