Fig. 5.

Incremental discriminative ability of biomarkers to predict CT positivity. Plots show the difference in Area under the ROC curve (AUC) with 95% confidence intervals (bars) of logistic regression models combining age, time interval (injury to needle time) as well as clinical parameters included in current CT rules with and without biomarkers. Panels are presented for the overall sample (n=2867), according to stratum (ER, Admission, ICU), and for the mild (GCS 13–15; GCS 13–14; GCS 15) groups. Six biomarkers are considered separately and in combination (“all”). The dotted line indicates the predictive value of the clinical parameters and serves as a reference. The absolute values are presented in the Supplementary material, Table S7.