Classification Systems for Moderate-Severe Traumatic Brain Injury

There is no single, standardized clinical instrument or biomarker available to categorize traumatic brain injury (TBI) severity that is deemed the official gold standard for classification. Instead, the current approach is to rely on several criteria to establish severity. There are a number of different classification systems in place that are used and these different systems utilize different indicators. Heterogeneity across classification systems introduces a challenge for recruitment into research studies and obscures knowledge of how different degrees of severity impact outcomes, thus, limiting generalizability across investigations. There is no comprehensive review and summary of these criteria into one single system. The aim of the current paper is to provide a brief overview of TBI and narrative review of available systems used to formally classify TBI severity. Additionally, we propose minimum standardized criteria that should be reported in future TBI research to differentiate between mild and moderate-severe injuries in the absence of one or more determining criteria. Ultimately, this will help facilitate standardized inclusion criteria and afford better comparison and generalizability across studies that may lead to the development of severity-specific medical interventions.