External evaluation of Brain Injury Guideline (BIG) low risk criteria for traumatic brain injury

Abstract

Background

Fewer than 20 % of traumatic brain injury (TBI) cases with traumatic intracranial hemorrhage (ICH) result in clinical deterioration. The Brain Injury Guideline (BIG) criteria were published in 2014 and categorize patients with TBI into three risk groups (BIG 1, 2, and 3) based on CT scan findings, neurological examination, anti-coagulant/platelet medications, and intoxication. Early data is promising, suggesting no instances of neurosurgical intervention or death in the low-risk BIG1 category within 30 days. We sought to externally validate the BIG criteria and identify patients with TBI at low risk of clinical deterioration. We hypothesized that patients meeting the BIG1 low risk criteria have less than a 1 % risk of death or neurosurgical intervention.

Methods

We performed a retrospective cohort study of a level 1 trauma center's trauma registry records from 2011 to 2022 to identify patients with head trauma. We abstracted demographics, injury characteristics, clinical course, CT imaging results, and outcomes, and we categorized patients according to the BIG criteria. The Clopper-Pearson Exact method was used to estimate outcome frequency with confidence intervals. The primary outcome was death or neurosurgical intervention within 30 days. Secondary outcomes included progression on repeat head CT (RHCT), ICU admission with neurocritical care intervention, and TBI-related hospital readmission within 30 days.

Results

A total of 1714 patients with TBI with ICH were identified from the trauma registry. 325 patients were excluded due to missing data, pregnancy, incarceration, polytrauma, or GCS < 13, leaving 1389 for analysis. 193 patients (13.9 %) were classified as BIG1. No patients classified as BIG1 experienced the primary outcome measures of death or neurosurgical intervention (95 % confidence interval [CI]: 0 %–1.9 %). The number of patients who experienced the secondary outcome measures of progression on RHCT, ICU admission with neurocritical care intervention, or TBI-related hospital readmission within 30 days were 9 (4.7 %, 95 % CI: 2.2 %–8.7 %), 1 (0.5 %, 95 % CI: 0 %–2.9 %), and 4 (2.1 %, 95 % CI: 0.6 %–5.2 %), respectively.

Conclusion

BIG1 criteria identified a low-risk subset of patients with TBI with ICH. However, an upper 95 % CI of 1.9 % does not exclude the risk of neurologic deterioration being <1 %. Validation of these criteria in larger cohorts is warranted.