An initial Glasgow Coma Scale score of 8 or less does not define severe brain injury.

The wide-spread use of an initial 'Glasgow Coma Scale (GCS) 8 or less' to define and dichotomise 'severe' from 'mild' or 'moderate' traumatic brain injury (TBI) is an out-dated research heuristic that has become an epidemiological convenience transfixing clinical care. Triaging based on GCS can delay the care of patients who have rapidly evolving injuries. Sole reliance on the initial GCS can therefore provide a false sense of security to caregivers and fail to provide timely care for patients presenting with GCS greater than 8. Nearly 50 years after the development of the GCS - and the resultant misplaced clinical and statistical definitions - TBI remains a heterogeneous entity, in which 'best practice' and 'prognoses' are poorly stratified by GCS alone. There is an urgent need for a paradigm shift towards more effective initial assessment of TBI.