The Relationship of the FOUR Score to Patient Outcome: A Systematic Review.

Ching C Foo,Paul M Brennan,James J.M Loan

doi:10.1089/neu.2018.6243

Abstract

The Full Outline of UnResponsiveness (FOUR) score assessment of consciousness replaces the Glasgow Coma Scale (GCS) verbal component with assessment of brainstem reflexes. A comprehensive overview studying the relationship between a patient's FOUR score and outcome is lacking. We aim to systematically review published literature reporting the relationship of FOUR score to outcome in adult patients with impaired consciousness. We systematically searched for records of relevant studies: CENTRAL, MEDLINE, EMBASE, Scopus, Web of Science, ClinicalTrials.gov, and OpenGrey. Prospective, observational studies of patients with impaired consciousness were included where consciousness was assessed using FOUR score, and where the outcome in mortality or validated functional outcome scores was reported. Consensus-based screening and quality appraisal were performed. Outcome prognostication was synthesized narratively. Forty records (37 studies) were identified, with overall low (n = 2), moderate (n = 25), or high (n = 13) risk of bias. There was significant heterogeneity in patient characteristics. FOUR score showed good to excellent prognostication of in-hospital mortality in most studies (area under curve [AUC], >0.80). It was good at predicting poor functional outcome (AUC, 0.80–0.90). There was some evidence that motor and eye components (also GCS components) had better prognostic ability than brainstem components. Overall, FOUR score relates closely to in-hospital mortality and poor functional outcome. More studies with standardized design are needed to better characterize it in different patient groups, confirm the differences between its four components, and compare it with the performance of GCS and its recently described derivative, the GCS-Pupils, which includes pupil response as a fourth component.

Highlights

Clinicians’ management decisions about acute traumatic brain injury (TBI) patients are guided by assessments of the person’s current state and may be influenced by their perceptions of its relation to the patient’s likely outcome.[1]
The Full Outline of UnResponsiveness (FOUR) score was developed for the assessment of level of consciousness in patients admitted to a neurointensive care unit.[7]
Studies were included if they reported data on patients with impaired consciousness of any cause, where level of consciousness was assessed using FOUR score, and where the outcome was reported in terms of mortality or a validated measure of functional outcome, such as modified Rankin Scale[9] or Glasgow Outcome Scale (GOS).[10]

Summary

Introduction

Clinicians’ management decisions about acute traumatic brain injury (TBI) patients are guided by assessments of the person’s current state and may be influenced by their perceptions of its relation to the patient’s likely outcome.[1] Internationally, the Glasgow Coma Scale (GCS) is the most widely used tool for assessing and communicating about a patient’s responsiveness.[2] All the three components—eye, motor, and verbal responses—relate to outcome,[3] as does the derived summation into the GCS score, albeit with some loss of information. The Full Outline of UnResponsiveness (FOUR) score was described by Wijdicks and colleagues. It is based on the eye and motor components of the Glasgow system, but the verbal component was removed and two new components added, namely brainstem reflexes and respiratory pattern. Each component is a 5-point scale, ranging from 0 to 4, with combined FOUR score ranging from 0 to 16, with 16 indicating the highest level of consciousness.

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