Kupas F et al. "Glasgow Coma Scale Motor Component ("Patient Does Not Follow Commands") Performs Similiarly to Total Glasgow Coma Scale in Predicting Severe Injury in Trauma Patients." Annals of Emergency Medicine. December 2016.

Study Design:

• Retrospective analysis of Pennsylvania statewide trauma registry of 393,877 patients from 1999 to 2013
• Patients with initial Glasgow Coma Scale (GCS) <13 were compared to those with Glasgow Coma Scale Motor Component (GCS-m) <6 ("not following commands")

Outcomes:

• Injury Severity Score (ISS) >15
• ISS >24
• Death
• TICU Admission 
• Need for Surgery
• Need for Craniotomy

Results: Differences in sensitivty and specificity <5% were a priori set to be clinically non-significant

• Differences in sensitivity and specificity of GCS <13 scoring and GCS-m <6 scoring were less than 5% (difference of 2.5-4.9% for sensitivity, 1.2-2.0% for specificity)
• Full GCS scoring system was slightly more sensitive in all outcomes, GCS-m score was slightly more specific in all outcomes

Take Home Points:

• Full GCS score has been shown to be inaccurate and unreliable among health care workers, somewhat due to its complexity.
• Binary nature of GCS-m score (following commands or not) would increase agreement among all healthcare providers (pre-hospital, ED, trauma) while providing similar accuracy.
• GCS-m <6 (patient "not following commands") performs similarly to more complicated full GCS score.

References:
1. Kupas F et al. "Glasgow Coma Scale Motor Component ("Patient Does Not Follow Commands") Performs Similiarly to Total Glasgow Coma Scale in Predicting Severe Injury in Trauma Patients." Annals of Emergency Medicine. December 2016.