Demographics and presenting features
| Within 6 hours of head injury (n=133) | Within 24 hours of head injury (n=265) | P value | |
| ED N/total n (non-missing data) (%) | |||
| Wellington | 89/133 (44.3) | 201/265 (75.8) | 0.065 |
| Hutt | 44/133 (68.8) | 64/265 (24.2) | |
| Age N/total n (non-missing data) (%) | |||
| Median (IQR) | 69.5 (39.0–83.3) | 69.0 (41.5–82.0) | 0.82 |
| Age range N/total n (non-missing data) (%) | |||
| 18–35 | 28/133 (21.1) | 54/265 (20.5) | 0.98 |
| 36–65 | 29/133 (21.8) | 60/265 (22.7) | |
| 66–99 | 76/133 (57.1) | 151/265 (56.8) | |
| Gender N/total n (non-missing data) (%) | |||
| Female | 48/131 (35.8) | 115/261 (44.1) | 0.144 |
| Male | 84/131 (62.7) | 146/261 (55.9) | |
| Ethnicity (prioritised) N/total n (non-missing data) (%) | |||
| Māori | 21/133 (15.7) | 39/265 (14.7) | 0.99 |
| Pacific | 4/133 (3) | 9/265 (3.4) | |
| NZ European | 86/133 (64.2) | 167/265 (63.0) | |
| Asian | 2/133 (1.5) | 5/265 (1.9) | |
| Other | 21/133 (15.7) | 45/265 (17.0) | |
| Antiplatelets/anticoagulants N/total n (non-missing data) (%) | |||
| Yes | 49/133 (37.3) | 104/265 (39.2) | 0.708 |
| Aspirin | 14/133 (10.5) | 32/265 (12.1) | 0.80 |
| Clopidogrel | 2/133 (1.5) | 6/265 (2.3) | 0.60 |
| Warfarin | 13/133 (9.8) | 23/265 (8.7) | 0.74 |
| Rivaroxaban | 7/133 (5.3) | 18/265 (6.8) | 0.54 |
| Dabigatran | 14/133 (10.5) | 27/265 (10.2) | 0.94 |
| Alcohol N/total n (non-missing data) (%) | |||
| Yes | 19/133 (14.2) | 52/265 (19.6) | 0.18 |
| Mechanism N/total n (non-missing data) (%) | |||
| Fall from height (>ground level) | 26/133 (19.4) | 38/265 (14.3) | 0.59 |
| Fall from standing height | 57/133 (43.3) | 132/265 (49.8) | |
| Motor vehicle accident | 18/133 (13.4) | 26/265 (9.8) | |
| Sport | 17/133 (12.7) | 33/265 (12.5) | |
| Assault | 11/133 (8.2) | 27/265 (10.2) | |
| Other | 4 (3.0) | 9/265 (3.4) | |
| Trauma N/total n (non-missing data) (%) | |||
| Isolated head injury | 95/133 (71.4) | 208/265 (78.5) | 0.26 |
| Polytrauma with fracture | 25/133 (18.7) | 34/265 (12.8) | |
| Polytrauma without fracture | 13/133 (9.7) | 23/265 (8.7) | |
| Lowest recorded GCS in ED N/total n (non-missing data) (%) | |||
| 15 | 106/133 (79.6) | 222/265 (84.4) | |
| 13–14 | 24/133 (18.0) | 37/265 (13.9) | 0.32 |
| 10–12 | 3/133 (2.2) | 5/265 (1.9) |
Results were considered significant if p values were <0.05.
Polytrauma is the presence of extracranial injuries in addition to head injury.
NZ, New Zealand.