Development and internal validation of the goliat score to predict 48-hour complications after minor/moderate traumatic brain injury in the emergency department: a single-center cohort study

Abstract

Background: Most patients with non-severe traumatic brain injury (TBI) do not develop complications after 24 h of hospital observation. Identifying low-risk patients could enable safe discharge and follow-up-potentially via telemedicine-while avoiding unnecessary cranial CT scans, particularly in older adults.

Methods: We performed a single-centre, consecutive cohort study (tertiary ED, Spain; 1 June 2019–31 December 2020). Adults with minor/moderate TBI (GCS 13–15) were included. The primary outcome was any clinically relevant complication within 48 h (neurological, cardiorespiratory, or death), ascertained by a structured 48-h telephone follow-up plus electronic health record review by assessors independent from clinical care. Candidate predictors (≤ 6 h) comprised baseline factors (age, sex, Charlson comorbidity index, prior anticoagulation), injury-severity signals (polytrauma-code activation, pupil abnormality, fluctuating GCS), physiology/haematology (systolic blood pressure, platelet count), and serum S100 (< 6 h). A multivariable logistic regression with prespecified functional forms (splines/transforms) and two interactions (sex×log[S100]; hypertension×SBP) was fitted. Internal validation used bootstrap/LOOCV with optimism correction and uniform shrinkage. Performance was assessed by AUC, Brier score, calibration (slope/intercept, plots), and decision-curve analysis (DCA). We defined a risk-stratified pathway at ~ 6 h (discharge vs. short observation vs. admission).

Results: Median age was 84 years (IQR 73–88), and 84.6% were ≥ 65 years. Acute complications occurred in 155 patients (29.5%). Independent predictors were age, sex, platelet count, systolic blood pressure, history of hypertension, S100B level at 6 h, anticoagulant treatment, and any high-risk clinical event (fluctuating GCS, moderate severity, pupil alteration, TBI code activation, anticoagulant reversal, polytrauma). Pathological CT findings did not show a significant contribution to the predictive model (LRT p = 0.10) and were not used. The Goliat score achieved an AUC of 0.72 (95% CI 0.68–0.77), good calibration (Hosmer–Lemeshow p = 0.18), and a Brier score of 0.195. Performance was comparable across age (< 65: AUC 0.70; ≥65: AUC 0.73) and sex subgroups. Using the Youden cut-off, 118 (76.1%) were predicted at high risk (sensitivity), while in those ones without complications 220 (59.5%) were classified at low risk (specificity). In total, of the 257 (49.0%) patients predicted at low risk, 37 had experienced complications.

Conclusions: The Goliat score is a novel clinical prediction tool for estimating the risk of acute complications in non-severe TBI that does not require cranial CT findings, potentially reducing unnecessary radiation exposure and ED resource use. By integrating easily obtainable variables and the biomarker S100B it could support safe discharge decisions, although requires prospective external validation before clinical adoption. By linking predicted risk to a risk-stratified clinical pathway, the score prioritizes safe discharge and targeted observation rather than routine CT reduction.