Wearing helmet (n=4075) | Not wearing helmet (n=2546) | P value | |
Skull vault fracture (%, n, 95% CI) | 5.8% (238, 5.2% to 6.6%) | 27.2% (695, 25.6% to 29.1%) | <0.001 |
Base of skull # (%, n, 95% CI) | 7.6% (308, 6.8% to 8.4%) | 25.8% (658, 24.2% to 27.6%) | <0.001 |
Pneumocephalus (%, n, 95% CI) | 2.3% (95, 1.9% to 2.8%) | 13.5% (345, 12.3% to 15.0%) | <0.001 |
Cerebral contusion (%, n, 95% CI) | 7.8% (317, 7.0% to 8.6%) | 21.7% (553, 20.2% to 23.4%) | <0.001 |
Subdural haematoma (%, n, 95% CI) | 5.9% (240, 5.2% to 6.7%) | 22.0% (561, 20.5% to 23.7%) | <0.001 |
Extradural haematoma (%, n, 95% CI) | 1.9% (77, 1.5% to 2.4%) | 12.3% (313, 11.1% to 13.6%) | <0.001 |
SAH (%, n, 95% CI) | 8.8% (358, 8.0% to 9.7%) | 24.1% (614, 22.5% to 25.8%) | <0.001 |
DAI (%, n, 95% CI) | 2.5% (100, 2.0% to 3.0%) | 3.7% (93, 3.0% to 4.5%) | 0.005 |
Brainstem compression (%, n, 95% CI) | 0.8% (34, 0.6% to 1.2%) | 3.1% (80, 2.5% to 3.9%) | <0.001 |
Brainstem injury involving haemorrhage (%, n, 95% CI) | 0.3% (12, 0.2% to 0.5%) | 1.3% (32, 0.9% to 1.8%) | <0.001 |
Cerebellar haematoma (%, n, 95% CI) | 0.2% (8, 0.1% to 0.4%) | 1.4% (34, 1.0% to 1.9%) | <0.001 |
DAI, diffuse axonal injury; SAH, sub-arachnoid haemorrhages; TARN, Trauma Audit and Research Network.