Table 3.

Multivariable logistic regression analysis of mortality by age subgroups

Variable	Subgroup analysis				Comparison between two groups
	≤ 64 years of age		≥ 65 years of age		≥ 65 years of agea
	OR (95% CI)	p-value	OR (95% CI)	p-value	OR (95% CI)	p-value
Age	1.038 (1.032, 1.044)	< 0.001	1.059 (1.050, 1.068)	< 0.001	4.585 (4.158, 5.055)	< 0.001
Female	0.723 (0.616, 0.850)	0.001	0.789 (0.696, 0.894)	< 0.001	0.813 (0.737, 0.897)	< 0.001
Trauma mechanism
Motor vehicle collision			Reference
Fall	1.290 (1.094, 1.522)	0.003	0.843 (0.725, 0.980)	0.026	1.224 (1.096, 1.366)	< 0.001
Blunt injury	0.463 (0.352, 0.610)	< 0.001	0.524 (0.377, 0.727)	< 0.001	0.462 (0.376, 0.568)	< 0.001
Penetrating injury	0.688 (0.464, 1.020)	0.064	0.701 (0.434, 1.132)	0.146	0.701 (0.523, 0.938)	0.017
Otherb	0.617 (0.504, 0.756)	< 0.001	0.681 (0.560, 0.827)	< 0.001	0.686 (0.596, 0.789)	< 0.001
Vital signs
SBP (mmHg)	0.986 (0.985, 0.988)	< 0.001	0.992 (0.990, 0.993)	< 0.001	0.989 (0.988, 0.990)	< 0.001
DBP (mmHg)	1.003 (1.002, 1.004)	< 0.001	1.002 (1.001, 1.003)	< 0.001	1.002 (1.002, 1.003)	< 0.001
HR (beats/min)	1.002 (1.001, 1.004)	0.011	1.003 (1.002, 1.005)	< 0.001	1.002 (1.001, 1.004)	< 0.001
RR (breath/min)	1.009 (1.007, 1.010)	< 0.001	1.004 (1.003, 1.005)	< 0.001	1.006 (1.005, 1.008)	< 0.001
BT (°C)
GCS	0.603 (0.593, 0.613)	< 0.001	0.678 (0.668, 0.688)	< 0.001	0.635 (0.629, 0.642)	< 0.001
EMR-ISS	1.028 (1.025, 1.031)	< 0.001	1.036 (1.033, 1.039)	< 0.001	1.033 (1.031, 1.035)	< 0.001

BT, body temperature; CI, confidence interval; DBP, diastolic blood pressure; EMR-ISS, excess mortality ratio–adjusted Injury Severity Score; GCS, Glasgow Coma Scale; HR, heart rate; OR, odds ratio; RR, respiratory rate; SBP, systolic blood pressure

^aReference group is ≤ 64 years of age

^bOther contains the low-frequency injury mechanisms, such as explosions or foreign bodies