Application and clinical utility of the Glasgow Coma Scale over time: a study employing the NIDRR traumatic brain injury model systems database.

OBJECTIVE To examine possible changes in Glasgow Coma Scale (GCS) scores related to changes in emergency management, such as intubation and chemical paralysis, and the potential impact on outcome prediction. PARTICIPANTS 10 228 patients from the Traumatic Brain Injury Model Systems national database. DESIGN Retrospective study examining 5-year epochs from 1987 to 2012. MAIN MEASURES GCS score assessed in the Emergency Department (GCS scores for intubated, but not paralyzed, patients were estimated with a formula using 2 of the 3 GCS components), Outcome: Functional Independence Measure (FIM) assessed at rehabilitation admission. RESULTS The rate of intubation prior to GCS scoring averaged 43% and did not increase across time. However, a clear increase over time was observed in the use of paralytics or heavy sedatives, with 27% of patients receiving this intervention in the most recent epoch. Estimated GCS scores classified 69% of intubated patients as severely brain injured and 8% as mildly injured. The GCS accounted for a modest, yet consistent, amount of variability (approximately 5%-7%) in FIM scores during most epochs. CONCLUSIONS Given the frequency of intubation and/or paralysis following brain injury in this sample, estimating GCS or exploring other means to gauge injury severity is beneficial, particularly because a portion likely did not sustain severe brain injury. There is no evidence for declining predictive utility of the GCS over time.