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RehabMeasures Instrument

Full Outline of UnResponsiveness Score

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Purpose

The FOUR is a clinical grading scale for use by medical professionals in the assessment of patients with severely impaired level of consciousness.

Link to Instrument

Instrument Details

Acronym FOUR

Assessment Type

Observer

Cost

Free

Diagnosis/Conditions

  • Brain Injury Recovery
  • Cardiac Dysfunction
  • Stroke Recovery

Key Descriptions

  • 4 components:
    1) eye responses
    2) motor responses
    3) brainstem reflexes
    4) respiration patterns
  • Each component has a maximal value of 4 (0-4).
  • Total possible score ranges 0-16, with lower scores indicating greater impairment.
  • Eye Response Scores:
    0) Eyelids remain closed with pain
    1) Eyelids closed but open to pain
    2) Eyelids close but open to loud voice
    3) Eyelids open but not tracking
    4) Eyelids open or opened, tracking, or blinking to command
  • Motor Response:
    0) No response to pain or generalized myoclonus status
    1) Extension response to pain
    2) Flexion response to pain
    3) Localizing to pain
    4) Thumbs-up, fist, or peace sign
  • Brainstem Response:
    0) Absent pupil, corneal, and cough reflex
    1) Pupil and corneal reflexes absent
    2) Pupil or corneal reflexes absent
    3) One pupil wide and fixed
    4) Pupil and corneal reflexes present
  • Respiration:
    0) Breathes at ventilator rate or apnea
    1) Breathes above ventilator rate
    2) Not intubated, irregular breathing
    3) Not intubated, Cheyne-Stokes breathing pattern
    4) Not intubated, regular breathing patterns
  • Full instructions available within body of original article via link provided above (Wijdicks et al., 2005).

Number of Items

20

Time to Administer

Less than 5 minutes

Required Training

Reading an Article/Manual

Age Ranges

Adult

18 - 64

years

Elderly Adult

65 +

years

Instrument Reviewers

Angela F. Davis, PT, MHS, NCS

ICF Domain

Body Structure
Body Function

Measurement Domain

General Health
Motor
Sensory

Considerations

  • The 4 components of the Full Outline of Unresponsiveness (FOUR) scale are equally weighted (Wijdicks, 2005)
  • The eye response component allows differentiation between a vegetative state and locked-in syndrome (Wijdicks, 2005)
  • The motor component includes a complex command to determine whether patients are alert and can detect signs of severe cerebral dysfunction (Wijdicks, 2005)
  • Identification of myoclonic status epilepticus in the motor component is a poor prognostic sign for patients with suspected anoxic brain injury (Wijdicks, 2005)
  • The brainstem components assess the pons, mesencephalon and medulla oblongata in varied combinations (Wijdicks, 2005)
  • The respiratory component includes Cheyne-Stokes respiration and irregular breathing that may indicate bihemispheric or lower brainstem dysfunction of respiratory control (Wijdicks, 2005)
  • This test is appropriate for patients who are intubated due to lack of verbal component, but inclusion of respiratory component (Wijdicks, 2005)
  • The respiratory component for patients who are intubated detects the presence or absence of respiratory drives (Wijdicks, 2005)
  • The FOUR scale is able to recognize possible brain death (with all components rated 0), locked-in syndrome, uncal herniation, vegetative state and the need for immediate medical or surgical intervention (Wijkicks, 2005 & 2006)
  • The FOUR scale can be used as a discriminative tool to establish baseline and rule in/out conditions noted above
  • The FOUR scale can be used as a predictive tool of future mortality or outcome
  • The FOUR scale can be used to evaluate change in consciousness over time with serial completions of the scale

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Brain Injury

back to Populations

Cut-Off Scores

Patients with Abnormal Consciousness in Neuro ICU: (Wijdicks, 2005; n=120; mean age 58.9 (range 45-70) years; upon admission or discovery of altered consciousness)

  • Sum of sensitivity and specificity maximized at FOUR total score of 9 (sensitivity=0.75; specificity=0.76) for prediction of in-hospital mortality
  • Range of scores above which the risk for in-hospital mortality is near 0 (FOUR > 12)

 

Traumatic Brain Injury:

  • FOUR total score < 6 predicts expected death (Jalali, 2014; n=104; mean age 41.38 (18.22) years; assessed within 24 hours of admission to ICU)
  • Sensitivity 68.4% (Jalali, 2014)
  • Optimal score to predict in-hospital mortality is FOUR total score 9 (sensitivity=73%; specificity=80%) (Okasha, 2014; n=60; mean age 29 (25-46 range) years; with TBI admitted to critical care medicine department)
  • Optimal score to predict poor outcome, defined as Glasgow Outcome Scale Extended score 1-4 is FOUR total score 11 (sensitivity=80%; specificity=64%) (Okasha, 2014)
  • Optimal score to predict endotracheal intubation is FOUR total score 11 (sensitivity=79%; specificity=100%) (Okasha, 2014)
  • Optimal score to predict early mortality is FOUR total score of 4 (sensitivity=0.92;specificity=0.87) (Gorji, 2015; n=80; mean age 33.80 (12.60) years; with TBI, intubated and admitted in ICU)
  • Optimal score to predict delayed mortality is FOUR total score of 6 (sensitivity=0.90; specificity=0.82) (Gorji, 2015)
  • Optimal score to predict mortality is FOUR total score of 7 (sensitivity=97.5%; specificity=88.2%) (Saika, 2015; n=138; mean FOUR score 11)
  • Optimal score to predict poor outcome, defined as Glasgow Outcome Scale score 1-3, was FOUR total score of 6 (sensitivity= 0.86; specificity=0.87) (Gorji, 2014; n=53; mean age 33.80 (12.60) years; with TBI admitted to ICU)
  • Optimal score to predict in-hospital mortality was FOUR total score of 4 (sensitivity=0.90; specificity=0.90) (Gorji, 2014)

 

Comatose Patients: (Wijdicks, 2011; n=381; mean age 61.6 (19.3) years; with primary neurological diagnoses admitted to ICU)

  • In subset of patients with Glasgow Coma Scale scores < 3
    • FOUR scores < 3 more likely to die than scores > 4 (33/43, 77% versus 31%; p value 0.0055)
    • Maximum sensitivity and specificity for this subset is FOUR scores <1 more likely to die than scores > 2 (26/31, 84% versus 11/25, 44%; p value 0.0039)

 

Neurosurgical Patients:

  • Cut-off point of total FOUR score of 14 showed sensitivity (0.77; 95% confidence interval, 0.69-0.84) and specificity (0.95;95% confidence interval, 0.90-0.97) for predicting poor outcomes (Akavipat, 2011; n=304; mean age 53.2 (15.8) years; newly admitted to neurosurgical unit or with altered mental status during admission)
  • Cut-off point of total FOUR score of 10 showed sensitivity (0.71;95% confidence interval, 0.55-0.83) and specificity (0.93; 95% confidence interval, 0.90-0.96) for predicting in hospital mortality (Akavipat, 2011)
  • Maximum sum of sensitivity (0.500) and specificity (0.957) for mortality is total FOUR score of 4 (Chen, 2013; n=101; mean age 64 (36.1) years; GCS score < 9; n=91 intubated and sedated)
  • No mortality at 30 days observed at FOUR scores > 9 (Chen, 2013)

 

Patients after Cardiac Arrest: (Fugate, 2010; n=136; mean age 62 (15) years; assessing in hospital mortality)

  • Specificity of sum FOUR score < 4 = 100%
  • Sensitivity of sum FOUR score < 4 = 47.6 %
  • Specificity of sum FOUR score < 8 = 91.1 %
  • Sensitivity of sum FOUR score < 8 = 90.5%
  • Specificity of sum FOUR score < 10 = 80.0 %
  • Sensitivity of sum FOUR score < 10 = 92.9%
  • 2-point improvement in FOUR score over serial examinations associated with survival (P = 0.041)

 

Interrater/Intrarater Reliability

Patients with Abnormal Consciousness in Medical ICU: (Iyer, 2009; n=100; mean age 63 (18.4) years; upon admission to Medical ICU)

  • Excellent interrater reliability (ICC = 0.99)

 

Patients with Abnormal Consciousness in Neuro ICU: (Wijdicks, 2005)

  • Excellent interrater reliability (Kw = 0.82, 95% confidence interval, 0.77-0.88)

 

Patients with Acute Neurologic Disease presenting to ED: (Stead, 2009; n=69; mean age unknown; upon admission to emergency department; 32 alert and 44 non-alert)

  • Excellent interrater reliability (Kw = 0.882)
  • Excellent interrater reliability (ICC = 0.975)

 

Patients with Impaired Consciousness presenting to ED: 

  • Excellent interrater reliability (K score=0.76, p < 0.01) (Kevric, 2011;n=203;various conditions)
  • Excellent interrater reliability (K score = 0.71-0.95) (Guijar, 2013; n=100;mean age 62(17) years; altered mental status due to medical causes)

 

Acute Neurologic Disease presenting to ICU: (Wolf, 2007; n=80)

  • Excellent interrater reliability
    • Kw=0.84 eye component
    • Kw=0.92 respiration component
    • Kw=0.89 brainstem component
    • Kw=0.73 motor component

 

Critically Ill Patients in Multiple ICUs: (Kramer, 2012; n=907; mean age 60 (range 48-72) years; admitted to multiple types of ICUs in 5 US hospitals; assessed within 1 hour of admission)

  • Excellent interrater reliability for total FOUR score (Kw = 0.92; 95% confidence internal, 0.90-0.93)
  • Excellent interrater reliability for patients on mechanical ventilation (Kw = 0.87; 95% confidence interval, 0.84-0.89)
  • Excellent interrater reliability for patients not on mechanical ventilation (Kw = 0.87; 95% confidence interval, 0.81-0.93)
  • Excellent interrater reliability for patients postoperatively (Kw = 0.89; 95% confidence interval, 0.85-0.92)
  • Excellent interrater reliability for patients not admitted postoperatively (Kw = 0.92; 95% confidence interval, 0.90-0.94)
  • Excellent interrater reliability for patients receiving active life sustaining therapies on day 1 (Kw = 0.89; 95% confidence interval, 0.87-0.91)
  • Excellent interrater reliability for patients not receiving active life sustaining therapies on day 1 (Kw = 0.88; 95% confidence interval, 0.82-0.95)

 

Traumatic Brain Injury: (Jalali, 2014)

  • Excellent interrater reliability (ICC = 0.98)

Internal Consistency

Traumatic Brain Injury:

  • Excellent internal consistency (Cronbach’s alpha = 0.89) (Sadaka, 2012; n=51; mean age 58 (range 18-87) years; within first 24 hours of admission to Neuro-ICU)
  • Excellent  internal consistency (Cronbach’s alpha = 0.87) (Mcnett, 2014; n=136; mean age 53.1 (21.40) years; admitted to Neurosurgical and Spine Surgical ICU at level 1 trauma center)
  • Excellent internal consistency (Cronbach’s alpha = 0.90) (Gorji, 2014)

 

Patients with Abnormal Consciousness in Medical ICU: (Iyer, 2009)

  • Excellent internal consistency (Cronbach’s alpha = 0.87)

 

Patients with Abnormal Consciousness in Neuro ICU: (Wijkicks, 2005)

  • Excellent internal consistency (Cronbach’s alpha = 0.86 for first rater; 0.87 for second rater)

Criterion Validity (Predictive/Concurrent)

Traumatic Brain Injury:

  • Excellent predictive validity for in-hospital mortality (area under the receiver operating characteristic (ROC) curve = 0.93 (Sadaka, 2012)
  • Adequate predictive validity for poor neurologic outcome at 3-6 months (area under the receiver operating characteristic (ROC) curve = 0.85) (Sadaka, 2012)      
  • Agreement between FOUR scale and patient outcome 44.9% (Jalali, 2014)
  • Agreement with Glasgow Coma Scale 43.8% (Jalali, 2014)
  • FOUR scale has better prediction for death than Glasgow Coma Scale, at 45.7% and 32.0% respectively, per Youden index (Jalali, 2014)    
  • Excellent predictive validity for mortality with 24-hour FOUR score (area under the receiver operating characteristic (ROC) curve=0.913) (McNett, 2014)
  • Adequate predictive validity for mortality with 72-hour FOUR score (area under the receiver operating characteristic (ROC) curve=0.837) (McNett, 2014)
  • Adequate predictive validity for in-hospital mortality (area under the receiver operating characteristic (ROC) curve=0.850) (Okasha, 2014)
  • Adequate predictive validity of brainstem reflexes sub-score of FOUR score in predicting mortality (area under the receiver operating characteristic (ROC) curve=0.822) (Okasha, 2014)
  • Adequate predictive validity for poor outcome, defined as Glasgow Outcome Scale Extended score 1-4 (area under the receiver operating characteristic (ROC) curve=0.813) (Okasha, 2014)
  • Adequate predictive validity of motor response of FOUR score in predicting poor outcome, defined as Glasgow Outcome Scale Extended score 1-4 (area under the receiver operating characteristic (ROC) curve=0.740) (Okasha, 2014)
  • Excellent predictive validity or endotracheal intubation (area under the receiver operating characteristic (ROC) curve=0.961) (Okasha, 2014)
  • Excellent predictive validity of eye response of FOUR score in predicting endotracheal intubation (area under the receiver operating characteristic (ROC) curve=0.944) (Okasha, 2014)
  • Excellent predictive validity of early mortality in patients who were intubated (area under the receiver operating characteristic (ROC) curve=0.90) (Gorji, 2015)
  • Adequate predictive validity of delayed mortality in patients who were intubated (area under the receiver operating characteristic (ROC) curve=0.86) (Gorji, 2015)
  • Excellent correlation with Glasgow Coma Scale (correlation coefficient=0.753) (Saika, 2015)
  • Excellent predictive validity of poor outcome, defined as Glasgow Outcome Scale 1-3 (area under the receiver operating characteristic (ROC) curve=0.95) (Gorji, 2014)
  • Excellent predictive validity of in-hospital mortality (area under the receiver operating characteristic (ROC) curve=0.92). (Gorji, 2014)

 

Patients with Abnormal Consciousness in Medical ICU: (Iyer, 2009)

  • Adequate predictive validity for in-hospital death (area under the receiver operating characteristic (ROC) curve = 0.86)
  • Adequate predictive validity for poor neurologic outcome, defined as Rankin score 3-6 (area under the receiver operating characteristic (ROC) curve = 0.75)

 

Patients with Abnormal Consciousness in Neuro ICU: (Wijdicks, 2005)

  • Adequate predictive validity for in-hospital mortality (area under the receiver operating characteristic (ROC) curve = 0.81)

 

Patients with Abnormal Consciousness with Multi-site ICUs: (Wijdicks, 2015; n=1,695; mean age 60.2 years; duration between hospital admission and ICU admission mean of 1.17 days; mean acute physiology score 38.4)

  • Adequate predictive validity associated with in-hospital mortality (area under receiver operating characteristic (ROC) curve = 0.702 (95% confidence interval, 0.661-0.744))
  • Adequate predictive validity associated with in-ICU mortality (area under receiver operating characteristic (ROC) curve = 0.742 (95% confidence interval, 0.694-0.790))

 

Critically Ill Patients in Multiple ICUs: (Kramer, 2012)

  • Adequate concurrent validity with Glasgow Coma Scale (GCS) (area under receiver operating characteristic (ROC) curve = 0.77 for FOUR score and 0.80 for GCS)

 

Neurosurgical Patients:

  • Adequate predictive validity for poor outcome (area under receiver operating characteristic (ROC) curve = 0.88 (95% confidence interval, 0.83-0.92)) (Akavipat, 2011)
  • Excellent predictive validity for in-hospital mortality (area under receiver operating characteristic (ROC) curve = 0.92 (95% confidence interval, 0.87-0.97)) (Akavipat, 2011)
  • Adequate predictive validity for mortality (area under receiver operating characteristic (ROC) curve = 0.768 (p<0.001;95% confidence interval, 0.664-0.872)) (Chen, 2013)
  • Poor predictive validity for poor outcome, defined as Glasgow Outcome Scale score 2-3 (area under receiver operating characteristic (ROC) curve = 0.682 (p=0.019; 95% confidence interval, 0.531-0.832)) (Chen, 2013)
  • Adequate predictive validity for favorable outcome, defined as Glasgow Outcome Scale score 4-5 (area under receiver operating characteristic (ROC) curve = 0.748 (p=0.001; 95% confidence interval, 0.624-0.871)) (Chen, 2013)

 

Altered Level of Consciousness presenting to ED: (Eken, 2009; n=185; post trauma to head or neurological complaints)

  • Adequate predictive validity for 3-month mortality (area under the receiver operating characteristic (ROC) curve=0.776)
  • Adequate predictive validity for hospital mortality (area under the receiver operating characteristic (ROC) curve=0.788)
  • Adequate predictive validity of poor outcome, defined as modified Rankin scale score of 3-6 (area under the receiver operating characteristic (ROC) curve = 0.751)

 

Patients with Multiple Trauma: (Baratloo, 2016; n = 89; mean age 31.9 (19.9) years; admitted to emergency department)

  • Adequate predictive validity of death with scoring at time of admission (area under the receiver operating characteristic (ROC) curve = 0.86; 95% confidence interval 0.79-0.94)
  • Excellent predictive validity of death with scoring 6 hours post admission (area under the receiver operating characteristic (ROC) curve = 0.93; 95% confidence interval 0.89-0.98)
  • Excellent predictive validity of death with scoring 12 hours post admission (area under the receiver operating characteristic (ROC) curve = 0.95; 95% confidence interval, 0.91-0.99)
  • Excellent predictive validity of death or disability with scoring at admission (area under the receiver operating characteristic (ROC) curve = 0.93; 95% confidence interval 0.87-0.98)
  • Excellent predictive validity of death or disability with scoring at 6 hours post admission (area under the receiver operating characteristic (ROC) curve = 0.96; 95% confidence interval 0.93-1.0)
  • Excellent predictive validity of death or disability with scoring at 12 hours post admission (area under the receiver operating characteristic (ROC) curve = 0.96; 95% confidence interval 0.92-1.0)
  • Sensitivity in predicting disease outcome of 86.9% at time of admission, 89.5% at 6 hours post admission and 89.5% at 12 hours post admission
  • Specificity for predicting disease outcome of 88.4% at time of admission, 100% at 6 hours post admission and 94.4% at 12 hours post admission
  • Positive predictive value of 86.8% at time of admission, 100% at 6 hours post admission and 94.4% at 12 hours post admission
  • Negative predictive value of 88.4% at time of admission, 91.5% at 6 hours post admission and 89.5% at 12 hours post admission

Construct Validity

Traumatic Brain Injury:

  • Excellent construct validity compared to the Glasgow Coma Scale (Spearman correlation coefficient = 0.97) (Sadaka, 2012)
  • Excellent construct validity compared to the Glasgow Coma Scale (Spearman correlation coefficient 0.87 at 24-hours; 0.90 at 72-hours) (McNett, 2014)

 

Patients with Abnormal Consciousness in Medical ICU (Iyer, 2009)

  • Excellent construct validity between first and second rater, compared to Glasgow Coma Scale (Spearman correlation coefficient = 0.98)

 

Patients with Abnormal Consciousness in Neuro ICU: (Wijdicks, 2005)

  • Excellent construct validity between first and second rater, compared to Glasgow Coma Scale (Spearman correlation coefficient = 0.92)

 

Patients with Abnormal Consciousness in Multi-site ICUs: (Wijdicks, 2015)

  • Excellent correlation with Glasgow Coma Scale (Spearman correlation coefficient = 0.85)

Responsiveness

Traumatic Brain Injury:

  • For every 1-point increase in FOUR scale total score associated with decreased odds of in-hospital mortality of 36% (OR 0.64; 95% confidence interval, 0.46-0.89) (Sadaka, 2012)
  • For every 1-point increase in FOUR scale total score associated with decreased odds of poor neurologic outcome of 29% (OR 0.71; 95% confidence interval, 0.57-0.88) (Sadaka, 2012)
  • For every 1-point increase in total FOUR score at 24-hours, 34% decrease in likelihood of mortality (OR=0.66; 95% confidence interval, 0.56-0.77) (McNett, 2014)
  • For every 1-point increase in total FOUR score at 72-hours, 24% decrease in likelihood of mortality (OR=0.76; 95% confidence interval, 0.66-0.87) (McNett, 2014)
  • For every 1-point increase in total FOUR score, 41% reduction in odds of in-hospital mortality (OR=0.59; 95% confidence interval, 0.44-0.79) (Okasha, 2014)
  • For every 1-point increase in total FOUR score, 46% reduction in odds of unfavorable outcome, defined as Glasgow Outcome Scale Extended scores 1-4 (OR=0.54; 95% confidence interval, 0.37-0.78) (Okasha, 2014)

 

Patients with Abnormal Consciousness in Medical ICU: (Iyer, 2009)

  • For every 1-point increase in FOUR scale total score associated with decreased odds of in-hospital death of 15% (OR 0.75; 95% confidence interval, 0.68-0.84)
  • For every 1-point increase in FOUR scale total score associated with decreased odds of poor neurologic outcome of 18% (OR 0.82; 95% confidence interval, 0.74-0.93)
  • Patients with Abnormal Consciousness in Neuro ICU: (Wijdicks, 2005)
  • For every 1-point increase in FOUR scale total score associated with decreased odds of in-hospital mortality of 20% (OR=0.80; 95% confidence interval, 0.72-0.88)
  • For every 1-point increase in FOUR scale total score associated with decreased odds of outcome defined as modified Rankin scale of 3 or more (OR=0.84; 95% confidence interval, 0.77-0.92)

 

Patients with Acute Neurologic Disease presenting to ED: (Stead, 2009)

  • For every 1-point increase in FOUR scale total score associated with decreased odds of in-hospital mortality (OR=.67; 95% confidence interval, 0.53-0.84)
  • For every 1-point increase in FOUR scale total score associated with better functional outcomes (OR=0.43; 95% confidence interval, 0.26-0.71), with poor outcome defined as Rankin score 3-6
  • For every 1-point increase in FOUR scale total score is associated with lower risk of overall mortality (OR = 0.84; 95% confidence interval, 0.79-0.89)

 

Stroke

back to Populations

Cut-Off Scores

Acute Ischemic Stroke: (Mansour, 2015; n=127; mean age 62.40 (1.11) years; with acute ischemic stroke defined as focal cerebral neurological dysfunction based on symptoms persisting > 24 hours)

  • Sum of sensitivity and specificity maximized at FOUR score of 11 on day-1 exam (sensitivity=0.84; specificity=0.57) for prediction of in-hospital mortality
  • Sum of sensitivity and specificity maximized at FOUR score of 8 on day-3 exam (sensitivity=1; specificity=0.86) for prediction of in-hospital mortality
  • Sum of sensitivity and specificity maximized at FOUR score of 11 on day-1 exam (sensitivity=0.79; specificity=0.85) for prediction of poor outcome, defined as modified Rankin Scale 3-6
  • Sum of sensitivity and specificity maximized at FOUR score of 11 on day-3 exam (sensitivity=0.84; specificity=0.94) for prediction of poor outcome, defined as modified Rankin Scale 3-6

Criterion Validity (Predictive/Concurrent)

Acute Ischemic Stroke:  (Mansour, 2015)

  • Adequate predictive validity for in-hospital mortality with day-1 scores (area under receiver operating characteristic (ROC) curve=0.796)
  • Excellent predictive validity for in-hospital mortality with day 3 scores (area under receiver operating characteristic (ROC) curve=0.977)
  • Adequate predictive validity for poor outcome with day-1 scores, defined as modified Rankin score of 3-6 (area under receiver operating characteristic (ROC) curve=0.865)
  • Excellent predictive validity for poor outcome with day-3 scores, defined as modified Rankin score of 3-6 (area under receiver operating characteristic (ROC) curve=0.909)

Responsiveness

Acute Ischemic Stroke: (Mansour, 2015)

  • For every 1-point increase from day-1 total FOUR score, 36% reduction in odds of in-hospital mortality (OR=0.64; 95% confidence interval, 0.52-0.79; p<0.001)
  • For every 1-point increase from day 3 total FOUR score, 74% reduction in odds of in-hospital mortality (OR=0.26; 95% confidence internal, 0.24-0.55; p<0.001)
  • For every 1-point increase from day-1 total FOUR score, 45% reduction in odds of unfavorable outcome, defined as modified Rankin score of 3-6 (OR=0.55; 95% confidence interval, 0.45-0.61; p<0.001)
  • For every 1-pint increase from day-3 total FOUR score, 47% reduction in odds of unfavorable outcome, defined as modified Rankin score of 3-6 (OR=0.53; 95% confidence interval, 0.43-0.65; p<0.001)

Bibliography

Akavipat P, Sookplung P, Kaewsingha P, Maunsaiyat P. Prediction of discharge outcomes with the Full Outline of Unresponsiveness (FOUR) Score in neurosurgical patients. Acta Med. 2011;65(3):205-210.  

Baratloo A, Shokravi M, Safari S, Aziz AK. Predictive value of Glasgow Coma Score and Full Outline of Unresponsiveness Score on the outcome of multiple trauma patients. Arch Iran Med. 2016;19(3):215-220.  

Chen B, Grothe C, Schaller K. Validation of a new neurological score (FOUR Score) in the assessment of neurosurgical patients with severely impaired consciousness. Acta Neurochir. 2013;155:2133-2139.  

Eken C, Kartal M, Bacanli A, Eray O. Comparison of the Full Outline of Unresponsiveness Score coma scale and the Glasgow Coma Scale in an emergency setting population [abstract]. European Journal of Emergency Medicine. 2009;16(1):29-36.  

Fugate JE, Rabinstein AA, Claassen DO, White RD, Wijdicks EFM. The FOUR Score predicts outcome in patients after cardiac arrest. Neurocrit Care. 2010; 13:205-210.  

Gorji MAH, Gorji AMH, Hosseini SH. Which score should be used in intubated patients’ Glasgow coma scale or full outline of unresponsiveness? In J Appl Basic Med Res. 2015;5(2):92-95.  

Gorji MAH, Hoseini SH, Gholipur A, Mohammadpur RA. A comparison of the diagnostic power of the Full Outline of Unresponsiveness scale and the Glasgow coma scale in the discharge outcome prediction of patients with traumatic brain injury admitted to the intensive care unit. Saudi J Anaesth. 2014;8(2):193-197.  

Guijar AR, Jacob PC, Nandhagopal R, Ganguly SS, Obaidy A, Al-Asmi AR. Full Outline of UnResponsiveness score and Glasgow Coma Scale in medical patients with altered sensorium: Interrater reliability and relation to outcome [abstract]. Journal of Critical Care. 2013;28(3):316e1-316e8.                

Iyer VN, Mandrekar JN, Danielson RD, Zubkov AY, Elmer JL, Wijdicks EFM. Validity of the FOUR Score Coma Scale in the medical intensive care unit. Mayo Clin Proc. 2009;84(8):694-701.  

Jalali R, Rezaei M. A comparison of the Glasgow Coma Scale score with Full Outline of Unresponsiveness Scale to predicts patients’ traumatic brain injury outcomes in intensive care units. Critical Care 嫩B研究院 and Practice.2014;2014:1-4.doi:10.1155/2014/289803.  

Kevric J, Jelinek GA, Knott J, Weiland TJ. Validation of the Full Outline of Unresponsiveness (FOUR) Scale for conscious state in the emergency department: comparison against the Glasgow Coma Scale. Emerg Med J. 2011;28:486-490.  

Kornbluth J, Bhardwaj A. Evaluation of coma: A critical appraisal of popular scoring systems. Neurocritical Care. 2010. doi:10.1007/s12028-010-9409-3.               

Kramer AA, Wijdicks EFM, Snavely VL, et al. A multicenter prospective study of interobserver agreement using the Full Outline of Unresponsiveness score coma scale in the intensive care unit. Crit Care Med. 2012;40(9):2671-2676.  

Mansour OY, Megahed MM, Abd Elghany EHS. Acute ischemic stroke prognostication, comparison between Glasgow Coma Score, NIHS Scale and Full Outline of UnResponsiveness Score in intensive care unit. Alexandria Journal of Medicine. 2015; 51:247-253.  

Mcnett M, Amato S, Gianakis A, et al. The FOUR Score and GCS as Predictors of Outcome After Traumatic Brain Injury. Neurocrit Care. 2014. doi: 10.1007/s12028-013-9947-6.  

Okasha AS, Fayed AM, Saleh AS. The FOUR Score Predicts Mortality, Endotracheal Intubation and ICU Length of Stay After Traumatic Brain Injury. Neurocrit Care. 2014. doi: 1007/s2028-014-9995-6.  

Riker RR, Fugate JE. Clinical Monitoring Scales in Acute Brain Injury: Assessment of Coma, Pain, Agitation, and Delerium. Neurocrit Care. 2014;21:S27-S37.                

Sadaka F, Patel D, Lakshmanan R. The FOUR Score Predicts Outcome in Patients After Traumatic Brain Injury. Neurocrit Care.2012;16:95-101.  

Saika, A, Bansal S, Philip M, Devi BI, Shukla DP. Prognostic value of FOUR and GCS score in determining mortality in patients with traumatic brain injury [abstract]. Acta Neurochirurgica.2015;157(8):1323-1328.                

Stead LG, Wijdicks EFM, Bhagra A, et al. Validation of a New Coma Scale, the FOUR Score, in the Emergency Department. Neurocrit Care.2009;10:50-54.  

Wijdicks EFM, Bamlet WR, Maramattom BV, Manno EM, McClelland RL. Validation of a NEW Coma Scale: The FOUR Score. Annals of Neurology. 2005; 58:585-593.  

Wijkicks EFM. Clinical Scales for Comatose Patients: The Glasgow Coma Scale in Historical Context and the New FOUR Score. Reviews in Neurological Diseases. 2006;3(3):109-117.  

Wijdicks EFM, Rabinstein AA. FOUR score and Glasgow Coma Scale in predicting outcomes of comatose patients: a pooled analysis. Neurology. 2011; 77:84-85.                

Wijdicks, EFM, Kramer AA, Rohs T, et al. Comparison of the Full Outline of UnResponsiveness score and the Glasgow Coma Scale in Predicting Mortality in Critically Ill Patients. Neurocrit Care. 2015;43(2):439-444.  

Wolf CA, Wijdicks EFM, Bamlet WR, McClelland RL. Further Validation of the FOUR Score Coma Scale by Intensive Care Nurses [abstract]. Mayo Clinic Proceedings. 2007;82(4):435-438.