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A Better Way to Measure Coma: Why the FOUR Score Matters for Patients and Families

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A Better Way to Measure Coma: Why the FOUR Score Matters for Patients and Families

When someone you love is in a coma, every number on the chart feels like a verdict about their future. For decades, the Glasgow Coma Scale (GCS) has been the default language for describing that state, but it leaves out crucial parts of the neurological exam. A newer tool called the FOUR Score offers a more complete, more consistent way to grade coma—one that can better capture brainstem function, breathing patterns, and subtle differences in responsiveness that matter deeply for prognosis.

What the FOUR Score Is and What It Measures

The FOUR Score—short for Full Outline of UnResponsiveness—was developed by neurologist Dr. Eelco (Ronald) Wijdicks and colleagues in the neurocritical care unit at the Mayo Clinic. Instead of relying on three domains like the GCS, it evaluates four key components of neurological function:

  • Eye response

  • Motor response

  • Brainstem reflexes

  • Respiration pattern

Each component is scored from 0 to 4, where 4 indicates normal or expected function and 0 indicates no response, giving a total score from 0 (deep coma) to 16 (fully responsive). In contrast to the GCS, the FOUR Score was designed from the outset to be usable in intubated patients and to capture details like pupil and corneal reflexes, herniation signs, and breathing drive.

Early validation work showed that the FOUR Score provides richer neurological detail than GCS, especially at the deepest levels of coma, and can distinguish conditions such as locked‑in syndrome that GCS may misclassify.

Why FOUR Score Is Often Better Than GCS

Clinicians and researchers have identified several practical advantages of the FOUR Score over the traditional Glasgow Coma Scale.

1. More comprehensive neurological picture

The most fundamental limitation of GCS is that it does not include brainstem reflexes or detailed respiratory patterns, and its verbal component cannot be applied in intubated patients. The FOUR Score directly addresses these gaps:

  • The brainstem component captures pupillary, corneal, and cough reflexes, as well as signs of transtentorial herniation.

  • The respiration component differentiates spontaneous breathing above the ventilator rate, irregular patterns, and complete apnea.

Because brainstem function and breathing patterns are central to prognosis in coma, the FOUR Score often gives a more clinically meaningful snapshot than a GCS number alone.

2. Better detail at the lowest levels of consciousness

In both research and bedside practice, a common problem with GCS is that many severely ill patients cluster at the lowest score of 3, even though their neurological states differ significantly. In a key validation study, patients who all had a GCS of 3 showed a wide range of FOUR Scores, revealing important differences in brainstem reflexes and respiratory drive.

That extra granularity matters for families and care teams trying to understand just how deep a coma is—and whether there are still preserved brainstem functions that may support recovery.

3. Strong inter‑rater reliability and clearer criteria

The FOUR Score was tested across neurologists, neuroscience nurses, and neurology residents and showed good to excellent agreement between raters, with weighted kappa values comparable to or better than GCS. Because the criteria for each 0–4 step are specific and observable, studies have found that it reduces variability in scoring and provides more consistent assessments across different clinicians.

For families, this can translate into fewer bewildering situations where three different doctors give three different coma grades on the same day—experiences that undermine trust and make it nearly impossible to understand what is really happening.

4. Prognostic value for outcomes and mortality

Multiple studies have evaluated how well the FOUR Score predicts in‑hospital mortality, length of stay, and functional outcomes, often comparing it directly with GCS:

  • In a medical intensive care study, the FOUR Score’s area under the ROC curve for in‑hospital death was 0.86, slightly better than the GCS at 0.82, and patients with a FOUR of 0 had higher mortality than those with the lowest GCS score.​

  • A 2024 analysis in traumatic brain injury found that the FOUR Score outperformed GCS in predicting hospital stay longer than 15 days and morbidity, with statistically higher accuracy.​

  • Other comparative studies report that both scales are useful, but the FOUR Score often shows equal or better sensitivity and specificity for poor outcomes, especially in critical care settings.

Taken together, these data suggest that the FOUR Score is at least as good—and in many contexts better—than GCS for forecasting risk and outcome, while also giving richer clinical detail.

What Needs to Happen for FOUR Score to Be Widely Used

Despite its advantages, the FOUR Score is still not as universally embedded in practice as the GCS, which has a decades‑long head start and is built into many electronic records and protocols. Changing that requires deliberate work at several levels of the health system.

Education and training for bedside teams

Articles aimed at nursing and ICU practice stress that the FOUR Score is easy to learn and apply once clinicians are familiar with its structure and acronyms such as EMBR (Eye, Motor, Brainstem, Respiration). Hospitals can:​

  • Incorporate FOUR Score teaching into orientation for ICU nurses, residents, and respiratory therapists

  • Use simulation scenarios that contrast GCS and FOUR in complex cases, such as intubated patients or suspected locked‑in syndrome

Hands‑on training helps clinicians see that the scale does not add complexity for its own sake; it simply captures what a good neuro exam already includes.​

Updating clinical guidelines and documentation

For the FOUR Score to become routine, it needs to be written into neuro‑ICU and trauma protocols, order sets, and documentation templates, rather than being left to individual preference. That includes:

  • Adding FOUR Score fields alongside or in place of GCS in ICU flowsheets

  • Referencing FOUR in institutional guidelines for coma assessment, prognostication, and communication with families

As more outcome studies accumulate—especially in general ICUs and emergency settings—professional societies may increasingly recommend or endorse the FOUR Score in their practice guidelines.

Continuing research and validation in diverse settings

Most early work on the FOUR Score came from specialized neuroscience ICUs. Recent and ongoing studies are expanding its validation to:

  • Mixed medical–surgical ICUs

  • Trauma centers and emergency departments

  • Populations with traumatic brain injury, stroke, and other critical neurologic conditions

This broader evidence base will clarify where FOUR Score provides the clearest advantage and how it can be adapted for different patient populations and resource settings.

Why this matters for caregivers and families

For families watching a loved one in a coma, tiny changes in a number can feel like the only tether to hope or reality. When three different clinicians use the same patient to produce three different coma scores in a single day, it is not just confusing—it is traumatizing, and it can erode confidence at a time when clarity is most needed.

The FOUR Score cannot eliminate all uncertainty, but it directly addresses some of the biggest pain points caregivers experience:

  • It separates out brainstem reflexes and breathing, so families and clinicians can talk concretely about what is preserved and what is not.

  • It gives finer gradations at the low end of responsiveness, reducing the sense that “a 3 is just a 3” with no nuance.

  • It has been shown to be reliable across different examiners, which can make day‑to‑day updates more consistent.

For caregivers who have lived through wildly conflicting coma grades, the promise of a more uniform, detailed, and clinically meaningful scale is not abstract. It can change how teams communicate, how prognosis is framed, and how quickly subtle changes are detected and acted upon.

As hospitals work to modernize neurocritical care, adopting tools like the FOUR Score is a concrete step toward more accurate, humane, and transparent assessment of some of the sickest patients we care for.

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