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.