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RehabMeasures Instrument

Glasgow Coma Scale

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Purpose

The GSC assesses a person's level of consciousness after injury. The scale can be used as part of an initial assessment or to monitor changes in consciousness over time.

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Instrument Details

Acronym GCS

Assessment Type

Observer

Administration Mode

Paper & Pencil

Cost

Free

Diagnosis/Conditions

  • Brain Injury Recovery
  • Cardiac Dysfunction
  • Pulmonary Disorders
  • Stroke Recovery

Key Descriptions

  • The Glasgow Coma Scale assesses motor, verbal and eye opening response using the criteria below.
  • Eyes:
    1) Does not open eyes
    2) Opens eyes in response to painful stimuli
    3) Opens eyes in response to voice
    4) Opens eyes spontaneously
    5) N/A
    6) N/A
  • Verbal:
    1) Makes no sounds
    2) Incomprehensible sounds
    3) Utters inappropriate words
    4) Confused, disoriented
    5) Oriented, converses normally
    6) N/A
  • Motor:
    1) Makes no movements
    2) Extension to painful stimuli
    3) Abnormal flexion to painful stimuli
    4) Flexion / Withdrawal to painful stimuli
    5) Localizes painful stimuli
    6) Obeys commands
  • Scores are summed across the three domains to determine an overall GCS score. Scores range from 3 (Deep coma) to 15 (fully awake person).

Number of Items

15

Time to Administer

10-15 minutes

Required Training

Reading an Article/Manual

Age Ranges

Adolescent

13 - 17

years

Adult

18 - 64

years

Elderly Adult

65 +

years

Instrument Reviewers

Initially reviewed by the Rehabilitation Measures Team; Updated with references for the TBI population by Erin Donnelly and the TBI EDGE task force of the Neurology Section of the APTA in 2012.

ICF Domain

Body Function

Measurement Domain

Cognition

Professional Association Recommendation

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (Vestibular EDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

For detailed information about how recommendations were made, please visit:  

Abbreviations:

 

HR

Highly Recommend

R

Recommend

LS / UR

Reasonable to use, but limited study in target group / Unable to Recommend

NR

Not Recommended


Recommendations based on level of care in which the assessment is taken:

 

Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility

Outpatient

Rehabilitation

Home Health

TBI EDGE

LS

NR

NR

NR

NR

 

Recommendations for use based on ambulatory status after brain injury:

 

Completely Independent

Mildly dependant

Moderately Dependant

Severely Dependant

TBI EDGE

N/A

N/A

N/A

N/A

 

Recommendations for entry-level physical therapy education and use in research:

 

Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)

TBI EDGE

Yes

Yes

Yes

Not reported

Considerations

Do you see an error or have a suggestion for this instrument summary? Please e-mail us!

Brain Injury

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Cut-Off Scores

Head Injury: (Balestreri et al, 2004; n = 358; mean age = 34 (16) years; Median GCS at admission = 6 (range from 3 to 13) points)

GCS score of 3 on presentation resulted in:

  • 65% mortality rate (Fearnside et al, 1993)
  • 100% mortality rate (Phuenpathom et al, 1993)

Normative Data

Head Injury: (Balestreri et al, 2004)

Glasgow Coma Scale Norms:

 

 

 

 

Year

n

GCS median (range)

GOS median (range) at six months

Age mean (SD)

1992

29

4 (3–11)

3 (1–5)

30 (17)

1993

39

6 (3–15)

4 (1–5)

32(15)

1994

40

5 (3–15)

4 (1–5)

30 (13)

1995

33

6 (3–12)

4 (1–5)

34 (16)

1996

43

5 (3–14)

3 (1–5)

33 (17)

1997

31

6 (3–14)

4 (1–5)

37 (17)

1998

52

7 (3–14)

4 (1–5)

36 (16)

1999

30

7 (3–14)

4 (1–5)

30 (15)

2000

27

7 (3–13)

3 (1–5)

38 (18)

2001

36

6 (3–12)

4 (1–5)

39 (16)

Criterion Validity (Predictive/Concurrent)

Brain Injury: (Balestreri et al, 2004; n = 358; mean age = 34 (16) years; Median GCS at admission = 6 (range from 3 to 15) points.

"The GCS's predictive validity, at least in predicting Glasgow Outcome Scores, is questionable. In some years the GCS demonstrated adequate correlations with the GOS (assessed 6 months later). In other years these correlations were poor."

GCS and GOS Predictive Validity:

 

 

 

Year

Strength

correlation; GOS 6 months after first GCS assessment

p

1992

Adequate

0.55

0.019*

1993

Adequate

0.39

0.015*

1994

Adequate

0.43

0.006*

1995

Adequate

0.42

0.016*

1996

Adequate

0.39

0.011*

1997

Poor

0.01

0.978

1998

Poor

0.21

0.131

1999

Poor

-0.16

0.932

2000

Poor

0.00

1.000

2001

Poor

0.29

0.087

*significant correlation

 

 

 

GCS = Glasgow Coma Scale
GOS = Glasgow Outcome Scores

 

 

 

 

Head Injury: presenting with a GCS of 3 six-months after injury: (Chamoun et al, 2009; n = 189; survivor mean age = 33.3 (12.8), patients who died 40.3 (16.97) years)

Glasgow Outcome Score

n (%)

1

18 (9.8%)

2

7 (3.7%)

3

35 (18.5%)

4

22 (11.6%)

Mortality

93 (49.2%)

Lost to follow-up

14 (7.4%)

Head Injury: (Balestreri et al, 2004)

Glasgow Coma Scale Norms:

 

 

 

 

Year

n

GCS median (range)

GOS median (range)

at six months

Age mean (SD)

1992

29

4 (3–11)

3 (1–5)

30 (17)

1993

39

6 (3–15)

4 (1–5)

32(15)

1994

40

5 (3–15)

4 (1–5)

30 (13)

1995

33

6 (3–12)

4 (1–5)

34 (16)

1996

43

5 (3–14)

3 (1–5)

33 (17)

1997

31

6 (3–14)

4 (1–5)

37 (17)

1998

52

7 (3–14)

4 (1–5)

36 (16)

1999

30

7 (3–14)

4 (1–5)

30 (15)

2000

27

7 (3–13)

3 (1–5)

38 (18)

2001

36

6 (3–12)

4 (1–5)

39 (16)

Construct Validity

Chronic Subdural Hematoma: (Amirjamshidi et al, 2006; n = 128; mean age = 57.2 (range = 9 to 88) years; Iranian sample)

  • Adequate: correlations between Glasgow Coma Scale (GCS) and the Glasgow Outcome Scale (GOS) r = 0.557
 

Head Injury (s/p blunt force trauma) (Shanmuganathan, et al., 2004; n= 21 patients with TBI secondary to blunt trauma mean age 37.8 (41.3) years; n=11 healthy control subjects, mean age 32.7 (19.2) years)

  • Adequate correlation between whole brain apparent diffusion coefficient histogram values and GCS score (r squared = .67)

Pediatric Disorders

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Interrater/Intrarater Reliability

ICU Patients: (Fischer et al, 2010; n = 267; mean age = 63 (17) years; both assessments within 1 hour of each other) 

  • Adequate: GCS inter-rater agreement = 71%
  • Excellent: GCS  agreement +/- 1 point = 90%
  • Inter-rater agreement was similar for neurologist and ICU staff

 

ICU Patients (multiple diagnoses including neurological): (Fischer et al, 2010; n = 267; mean age = 63 (17) years; both assessments within 1 hour of each other)

  • Adequate: GCS inter-rater agreement = 71%
  • Excellent: GCS agreement +/- 1 point = 90%
  • Inter-rater agreement was similar for neurologist and ICU staff

Criterion Validity (Predictive/Concurrent)

ICU (diagnosed with neurological diseases): (Ting et al., 2010; n= 154; mean age = 56.7 years; Total mortality ratio= 29.87%)

  • GCS score < 5= 50% mortality rate, significantly higher rate than those with GCS >5 (p<0.01).
  • GCS-Motor score ≤ 3 had a higher probability of mortality than patients with a GCS-M >3 (p< 0.01)
  • GCS-Eye opening and GCS-Verbal scores of 1 had higher probability of mortality than patients with scores > 1 (p< 0.01)
  • Patients had higher probability of mortality if GCS-E=1, CGS-V=1, and CGS-M=3 or less (p<.01).

Non-Specific Patient Population

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Cut-Off Scores

Standard Cut Scores:

  • > 13 = Minor brain injury
  • 9 - 12 = Moderate brain injury
  • < 8 = Severe brain injury

Interrater/Intrarater Reliability

Emergency Department Patients: (Gill et al, 2004; n = 116; median age = 54 (18–90) years; diagnosis, trauma = 28% Infection = 16%)

  • Exact agreement = 32%
  • GCS Component Agreement:
    • Adequate: Eye = 74%
    • Poor: Verbal = 55%
    • Adequate: Motor = 72%

 

Emergency Department Patients: (Gill et al, 2004; n = 116; median age = 54 (18–90) years; diagnosis, trauma = 28% Infection = 16%; ratings by 2 residency trained attending emergency physicians, scores within 5 minutes)

  • Exact agreement = 32% (Spearman rho=0.864)
  • GCS Component Agreement:
    • Adequate : Eye = 74% (rho=.757)
    • Poor : Verbal = 55% (rho=.665)
    • Adequate : Motor = 72% (rho=.808)

55-74% of paired measurements were identical, and 6-17% were 2 or more points apart. Agreement was only moderate with this diverse ED population.

Mixed Populations

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Cut-Off Scores

Pediatric TBI: (Chung et al, 2006;  = 309; mean age = 6.19 (2.27) years; outcomes assessed at 4.11 (2.07) years on average; Taiwanese sample)

  • Critical cut scores for the Glasgow Coma Scale score should be set slightly lower for children (5 points) than adults (8 points)
    • Low scores indicate the severity of brain injury and is considered predictive of death and potential of recovery.

Bibliography

Amirjamshidi, A., Abouzari, M., et al. (2007). "Glasgow Coma Scale on admission is correlated with postoperative Glasgow Outcome Scale in chronic subdural hematoma." J Clin Neurosci 14(12): 1240-1241. 

Balestreri, M., Czosnyka, M., et al. (2004). "Predictive value of Glasgow Coma Scale after brain trauma: change in trend over the past ten years." J Neurol Neurosurg Psychiatry 75(1): 161-162. 

Chamoun, R. B., Robertson, C. S., et al. (2009). "Outcome in patients with blunt head trauma and a Glasgow Coma Scale score of 3 at presentation." J Neurosurg 111(4): 683-687. 

Chung, C. Y., Chen, C. L., et al. (2006). "Critical score of Glasgow Coma Scale for pediatric traumatic brain injury." Pediatr Neurol 34(5): 379-387. 

Fearnside, M. R., Cook, R. J., et al. (1993). "The Westmead Head Injury Project outcome in severe head injury. A comparative analysis of pre-hospital, clinical and CT variables." Br J Neurosurg 7(3): 267-279. 

Fischer, M., Ruegg, S., et al. (2010). "Inter-rater reliability of the Full Outline of UnResponsiveness score and the Glasgow Coma Scale in critically ill patients: a prospective observational study." Crit Care 14(2): R64. 

Gill, M. R., Reiley, D. G., et al. (2004). "Interrater reliability of Glasgow Coma Scale scores in the emergency department." Ann Emerg Med 43(2): 215-223. 

Phuenpathom, N., Choomuang, M., et al. (1993). "Outcome and outcome prediction in acute subdural hematoma." Surg Neurol 40(1): 22-25. 

Shanmuganathan, K., Gullapalli, R. P., et al. (2004). "Whole-brain apparent diffusion coefficient in traumatic brain injury: correlation with Glasgow Coma Scale score." American journal of neuroradiology 25(4): 539-544.

Ting, H. W., Chen, M. S., et al. (2010). "Good mortality prediction by Glasgow Coma Scale for neurosurgical patients." Journal of the Chinese Medical Association 73(3): 139-143.