Table 5.

Multivariable factors associated with length of stay among survivors

Variable	Coefficient	95% CI		P value
Age*
Cubic spline among those aged 16–50	0.04	0.01	0.07	0.006
Cubic spline among those aged 51–75	0.07	−0.01	0.15	0.082
Cubic spline among those aged >75	−0.44	−0.80	−0.07	0.018
ATR injury cause
High fall	0.86	0.28	1.45	0.004
Low fall	Reference
Motor cyclist	1.95	1.31	2.59	<0.001
Motor vehicle occupant	2.56	1.99	3.12	<0.001
Other	0.54	−0.32	1.40	0.216
Other transport related	0.54	−0.61	1.70	0.355
Pedal cyclist	−0.61	−1.37	0.14	0.109
Pedestrian	2.56	1.84	3.29	0.000
Striking against or by object	−0.18	−1.25	0.89	0.737
Struck by or collision with a person	−0.96	−2.01	0.09	0.072
Arrival GCS motor
None (1)	Reference
Extension to pain (2)	−1.28	−4.98	2.42	0.498
Flexion to pain (3)	1.49	−1.12	4.09	0.263
Withdraws to pain (4)	−3.93	−5.57	−2.29	<0.001
Localises pain (5)	−3.82	−4.73	−2.90	<0.001
Obeys commands (6)	−8.01	−8.60	−7.43	<0.001
Not stated	−6.29	−7.30	−5.28	<0.001
Highest AIS score
1	−1.24	−8.35	5.87	0.732
2	−1.29	−2.92	0.35	0.123
3	Reference
4	2.28	1.88	2.67	<0.001
5	4.61	4.06	5.16	<0.001
6	8.18	3.14	13.22	0.001
Second-highest AIS score
1	−4.32	−5.00	−3.65	<0.001
2	−3.18	−3.58	−2.78	<0.001
3	Reference
4	5.35	4.36	6.34	<0.001
5	10.82	8.32	13.33	<0.001
NA	−4.50	−5.11	−3.89	<0.001
Shock-index grouped in quartiles
First quartile	Reference
Second quartile	0.27	−0.17	0.71	0.227
Third quartile	0.62	0.16	1.09	0.009
Fourth quartile	2.61	2.12	3.11	<0.001
Missing	−1.07	−2.30	0.16	0.089
Cardiac arrest on arrival	−14.73	−24.78	−4.69	0.004

*No reference category exists for age as the cubic splines represent non-linear relationships; resultant ORs are not easily interpretable.

AIS, Abbreviated Injury Scale; ATR, Australian Trauma Registry; GCS, Glasgow Coma Scale.