Table 1.

Demographic and clinical characteristics of the whole sample and distributed by the derivation and validation sets

Variable	All N = 9465	Derivation N = 5976	Validation N = 3489	p value
Age (years)	49 (33–65)	48 (33–65)	48 (33–63)	0.183
Age (groups)				0.145
< 50	53.7	53.6	53.8
50–65	22.8	22.3	23.7
65–75	12.6	12.7	12.3
> 75	11.0	11.4	10.2
Sex (% male)	77.7	77.8	77.6	0.800
PRECOAG	13.1	13.7	12.0	0.190
Pre-hospital attention	77.6	76.1	80.1	< 0.001
Pre-hospital intubation	24.7	25.0	24.3	0.421
Type of injury				0.005
Road Traffic accident	42.8	43.2	42.2
Fall	27.8	27.9	27.6
Occupational accident	7.9	7.8	8.0
Sport related	5.6	5.8	5.2
Assault	4.9	4.3	6.0
Self-injury	6.0	6.0	6.1
Unknown	1.9	1.8	2.2
High-risk mechanism	38.0	38.1	37.8	0.740
Mechanism penetrant	6.1	5.8	6.5	0.187
Pupils				0.486
Normal	88.9	88.7	89.3
Unilateral mydriasis	6.8	7.1	6.4
Bilateral mydriasis	4.3	4.3	4.2
GCS	14 (9–15)	15 (9–15)	14 (9–15)	0.896
GCS ≤ 8 (%)	24.4	24.5	24.1	0.667
MAIS-Head	41.9	41.7	42.3	0.562
MAIS-Thorax	38.1	39.0	36.5	0.119
MAIS-Abdomen	12.3	12.0	12.7	0.375
MAIS-Ext Upper	2.8	2.7	3.1	0.257
MAIS-Ext Lower	17.7	17.7	17.7	0.964
MAIS-External	1.0	1.1	1.0	0.602
Haemodynamic failure	22.0	22.4	21.2	0.179
Respiratory failure	11.8	11.5	12.4	0.213
Coagulopathy	15.9	15.7	16.3	0.517
Mechanical ventilation	48.4	49.8	45.9	< 0.001
Massive haemorrhage	6.0	6.5	5.3	0.026
TRISS (% mort)	5.7 (1.7–21.4)	5.7 (1.7–21.5)	5.6 (1.6–21.3)	0.103
ICU LOS (days)	4 (2–10)	4 (2–10)	4 (2–9)	0.235
Hospital LOS (days)	12 (6–26)	12 (6–25)	11 (5–24)	0.249
30-day mortality	12.2	12.6	11.6	0.190

Values expressed as percentages or median (Interquartile range)

PRECOAG, prior treatment with antiplatelets or anticoagulants; PRE-INTUB, pre-hospital intubation; GCS, Glasgow Coma Score; AIS, Abbreviated Injury Scale; MAIS, AIS ≥ 3; MV, mechanical ventilation; TRISS, Trauma and Injury Severity Score; ICU, intensive care unit; LOS, length of stay; p value, calculated using Chi-square test or Mann–Whitney test