Glasgow Coma Scale (GCS)


Glasgow Coma Scale (GCS) Evaluation Summary

  What does the tool measure? To describe the depth and duration of impaired consciousness or coma.
  What types of clients can the tool be used for? The GCS can be used with individuals with traumatic brain injury, cerebrovascular events, nontraumatic coma, cardiac arrest, and toxic ingestions.
  Is this a screening or assessment tool? Assessment
Time to administer Not reported.
  Versions Pediatric Glasgow Coma Scale
Other Languages Chinese
Measurement Properties
  Reliability – One study examined the internal consistency of the GCS and reported excellent internal consistency. 
– Two studies examined the inter-rater reliability of the GCS using kappa statistics. One study reported adequate inter-rater reliability and the other reported excellent inter-rater reliability for all three GCS subscales.

Predictive validity: 
– Three studies examined the predictive validity of the GCS. One reported that the GCS adequately predicted stroke mortality. One study reported that the total GCS score predicted acute mortality with 87% accuracy using just the Best eye response and Best motor response subscales, and with 88% accuracy using all three subscales. One study
reported that the GCS was able to predict both 2-week mortality and 3-month recovery
from stroke.

Convergent validity:
– One study examined the convergent validity of the GCS with the 60-Second Test (SST) and reported an excellent correlation using Spearman’s rho.

  Floor/Ceiling Effects No studies have examined floor/ceiling effects of the GCS in patients with stroke.
  Sensitivity/ Specificity Not reported.
  Does the tool detect change in patients? – One study examined the responsiveness of the GCS and reported that it had poor sensitivity to change.
  Acceptability Caution should be used in interpreting the scores of intubated clients, or clients with dysphasia or aphasia.
Feasibility The GCS is a short measure that requires no additional equipment. Although training is not required, it is recommended as the measure is more reliable when
completed by an experienced clinician. The scale is simple to score and cutoffs are well established in this measure.
How to obtain the tool? The GCS is available free online from the following website: