Combining the new injury severity score with an anatomical polytrauma injury variable predicts mortality better than the new injury severity score and the injury severity score: a retrospective cohort study

Table 2 ISS, NISS, polytrauma, and physiologic scores

Model	Variables (all include age, gender, and Charlson score)	OR for ISS or NISS (95 % CI)	OR for polytrauma, anatomical definition, yes/no (95 % CI)	OR for RTS (95 % CI)	C-statistic
1a	ISS	1.17 (1.16, 1.18) **	-	-	0.887
1b	NISS	1.11 (1.10, 1.11) **	-	-	0.902
2a	ISS + RTS	1.12 (1.11, 1.14)**	-	0.40 (0.37, 0.43)**	0.918
2b	NISS + RTS	1.08 (1.08, 1.09)**	-	0.44 (0.41, 0.48)**	0.926
3a	ISS + polytrauma	1.18 (1.17, 1.20)**	0.60 (0.46, 0.79)**	-	0.887
3b	NISS + polytrauma	1.10 (1.10, 1.11)**	2.48 (1.98, 3.11)**	-	0.904
4a	ISS + RTS + polytrauma	1.13 (1.12, 1.15)**	0.69 (0.51, 0.93)*	0.40 (0.37, 0.43)**	0.918
4b	NISS + RTS + polytrauma	1.08 (1.07, 1.09)**	1.98 (1.53, 2.54)**	0.45 (0.42, 0.49)**	0.928
5a	ISS + GCS + SBP + polytrauma	1.14 (1.12, 1.15)**	0.70 (0.52, 0.93)*	-	0.913
5b	NISS + GCS + SBP + polytrauma	1.08 (1.07, 1.09)**	1.98 (1.54, 2.54)**	-	0.924

*p < 0.05 **p < 0.001
Abbreviations: CI 95 % confidence interval, GCS Glasgow Coma Scale, ISS Injury Severity Score, NISS New Injury Severity Score, OR odds ratio, RTS Revised Trauma Score, SBP Systolic blood pressure

ISSN: 1757-7241