Full Outline of UnResponsiveness (FOUR Score)
Assesses level of consciousness, including in people who cannot speak.
By Claire White
- Clinician-administered, usable at the bedside even when a person is intubated.
- Four components (eye, motor, brainstem reflexes, and respiration), each scored 0 to 4.
- The total runs from 0 to 16. It can be graded in a few minutes.
- The eye component can be scored on two blinks to command, so it registers locked-in syndrome.
Psychometrics
Total-score coefficients from the 2005 validation in 120 intensive care patients (Wijdicks et al.). Higher is better.
What does the FOUR Score measure?
The FOUR Score rates four parts of the neurological exam. Because none of them is speech, it can be scored on a person who is intubated, where the Glasgow Coma Scale loses its verbal component. The brainstem and respiration components also give it detail below the floor of the older scale.
| Component | What it rates | Range |
|---|---|---|
| Eye response | Eyelid opening, tracking, and blinking to command | 0 to 4 |
| Motor response | Hand positions to command, and the response to pain | 0 to 4 |
| Brainstem reflexes | Pupillary, corneal, and cough reflexes | 0 to 4 |
| Respiration | Breathing pattern, or how the person triggers the ventilator | 0 to 4 |
What does a FOUR Score mean?
The total runs from 0 to 16 and is reported alongside the four component scores, because the profile carries information the sum does not. There are no published severity bands. The literature does not divide 0 to 16 into named grades, so the number is read against the same person's earlier scores and against the anchors at each end.
Sixteen means every component is at its top grade. Zero means every component is absent, and the original paper states that this should alert the examiner to consider a brain death evaluation. In between, the validation cohort of 120 intensive care patients showed a steady gradient. Each 1-point increase in the total was associated with about 20 percent lower odds of in-hospital death. Above a total of 12 the risk of in-hospital death in that cohort was close to zero. The cutoff that maximised sensitivity plus specificity for in-hospital death was a total of 9, at 0.75 sensitivity and 0.76 specificity.
These are group-level associations. The score is reference information for the care team, tracked over time, not a determination about one person.
How the FOUR Score is administered
- Administered by
- Neuroscience nurses, neurology residents, and neurointensivists in the validation study. Later validated with general intensive care nurses.
- Time to administer
- A few minutes
- Equipment
- Sterile saline drops or a cotton swab for the corneal reflex, tracheal suctioning for the cough reflex, and the ventilator monitor in ventilated patients
- Training required
- No certification. Raters in the validation study had a 20-minute video instruction and a one-page written guide.
- Age range
- Adults. The validation cohort averaged 59 years.
- Copyright
- The published scoring figure is copyright Mayo Foundation.
Which conditions is the FOUR Score used for?
Related instruments
- Modified Rankin Scale (mRS)The outcome scale used at three months in the FOUR Score validation
- NIH Stroke Scale (NIHSS)Stroke severity at the bedside, when the cause is a stroke rather than a general critical illness
- Montreal Cognitive Assessment (MoCA)What gets used later, once the person is awake enough to be tested on cognition
FOUR Score questions, answered
How is the FOUR Score scored?
Four components are each graded from 0 to 4 and added together, so the total runs from 0 to 16. The components are eye response, motor response, brainstem reflexes, and respiration. Unlike the Glasgow Coma Scale there is no verbal component, which is why the score still works when someone is intubated.
What is the difference between the FOUR Score and the Glasgow Coma Scale?
The FOUR Score drops the verbal component and adds brainstem reflexes and breathing pattern. That gives it room at the bottom of the range where the Glasgow Coma Scale runs out. In the validation study a Glasgow Coma Scale total of 3 was recorded 34 times, and only 9 of those were also a FOUR Score of 0. The other 25 spread across FOUR Scores of 1 to 8, which means the brainstem and respiration components were separating patients the older scale could not.
How does the FOUR Score detect locked-in syndrome?
Through the eye component. A score of 4 can be earned by tracking a finger or by two blinks on command, so someone who is fully aware but can move nothing except the eyelids still scores at the top of that component. The instructions call this out directly as the way the scale recognises locked-in syndrome.
What does a FOUR Score of 0 mean?
Every component is at its lowest grade: no eyelid opening to pain, no motor response, absent pupillary, corneal, and cough reflexes, and no breathing above the ventilator. The original paper states that when all categories are graded 0 the examiner should consider a brain death evaluation. In a medical intensive care unit study, patients whose lowest FOUR Score was 0 had 89 percent in-hospital mortality, against 71 percent for those whose lowest Glasgow Coma Scale score was 3.
Who can administer the FOUR Score?
Nurses, residents, and intensivists all did so in the validation work. Raters there watched a 20-minute video instruction and worked from a one-page written guide. A separate study with general intensive care nurses found weighted kappa agreement between 0.73 and 0.92 across the four components.
Does the FOUR Score predict whether someone will survive?
It carries prognostic information but it is not a prognosis. In the validation cohort of 120 patients, each 1-point increase in the total was associated with about 20 percent lower odds of in-hospital death, and the area under the ROC curve for predicting in-hospital death was 0.81, the same as the Glasgow Coma Scale. Above a total of 12 the risk of in-hospital death in that cohort was close to zero. These are group-level associations and reference information for the care team, not a determination about one person.
Evidence, psychometrics and provenance
Created by Eelco Wijdicks and colleagues at the Mayo Clinic and published in 2005. The validation enrolled 120 intensive care patients between July and September 2004, spread evenly across alert, drowsy, stuporous, and comatose states, each rated by two of nine raters drawn from neuroscience nurses, neurology residents, and neurointensivists.
- Agreement, intensive care nurses
- κw 0.73 to 0.92 by component (Wolf et al., 2007)
- Agreement, medical ICU
- κw 0.96 to 1.00 by component (Iyer et al., 2009)
- Prediction of in-hospital death
- Area under the ROC curve 0.81, matching the GCS (Wijdicks et al., 2005)
References
- 1.Wijdicks EF, Bamlet WR, Maramattom BV, Manno EM, McClelland RL. Validation of a new coma scale: The FOUR score. Ann Neurol. 2005;58(4):585-593.
- 2.Wolf CA, Wijdicks EF, Bamlet WR, McClelland RL. Further validation of the FOUR score coma scale by intensive care nurses. Mayo Clin Proc. 2007;82(4):435-438.
- 3.Iyer VN, Mandrekar JN, Danielson RD, Zubkov AY, Elmer JL, Wijdicks EF. Validity of the FOUR score coma scale in the medical intensive care unit. Mayo Clin Proc. 2009;84(8):694-701.
This assessment uses a validated instrument and is reference information, not a diagnosis.