Table 4.

Multivariate performance of CT models

Model	Complete cohort					Active treatment cohort
	R2	Gain in R2	AUC (95% CI)	Gain in AUC	p value	R2	Gain in R2	AUC (95% CI)	Gain in AUC	p value
6-month mortality
Base	0.708		0.943 (0.896–0.991)			0.578		0.917 (0.847–0.987)
Base + Marshall	0.739	+ 0.031	0.947 (0.902–0.992)	+ 0.004	0.720	0.608	+ 0.030	0.911 (0.837–0.985)	− 0.006	0.749
Base + Rotterdam	0.753	+ 0.045	0.953 (0.911–0.995)	+ 0.010	0.328	0.588	+ 0.010	0.914 (0.842–0.986)	− 0.003	0.719
Base + Helsinki	0.792	+ 0.084	0.963 (0.928–0.999)	+ 0.020	0.220	0.668	+ 0.090	0.931 (0.868–0.993)	+ 0.014	0.588
Base + Stockholm	0.741	+ 0.033	0.952 (0.909–0.994)	+ 0.009	0.410	0.611	+ 0.033	0.919 (0.849–0.988)	+ 0.002	0.933
6-month unfavorable outcome*
Base	0.526		0.885 (0.806–0.964)			0.405		0.823 (0.709–0.937)
Base + Marshall	0.673	+ 0.147	0.933 (0.876–0.990)	+ 0.048	0.099	0.594	+ 0.189	0.898 (0.813–0.983)	+ 0.075	0.093
Base + Rotterdam	0.672	+ 0.146	0.930 (0.869–0.992)	+ 0.045	0.124	0.590	+ 0.185	0.892 (0.802–0.982)	+ 0.069	0.123
Base + Helsinki	0.619	+ 0.093	0.917 (0.846–0.988)	+ 0.032	0.159	0.514	+ 0.109	0.876 (0.771–0.980)	+ 0.053	0.121
Base + Stockholm	0.639	+ 0.112	0.927 (0.857–0.996)	+ 0.042	0.130	0.545	+ 0.140	0.901 (0.808–0.994)	+ 0.078	0.052

Differences in AUC were compared using the DeLong test. Base model: age + GCS motor score + pupil responsiveness. AUC, area under the curve; CI, confidence interval; CT, computerized tomography; GOS, Glasgow Outcome Scale

*Defined as GOS 1–3; missing for 4 patients