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

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, , 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.

Recovery from disorders of consciousness: mechanisms, prognosis and emerging therapies

“…Hypothermia, in particular, affects drug metabolism, thus further confounding the examination. Clinical scoring systems used in these examinations include the Glasgow Coma Scale 3 and the Full Outline of UnResponsiveness (FOUR) 77 , with the latter showing potential advantages over the former for the prediction of in-hospital mortality and functional outcomes 78 . For patients with SAH, the World Federation of Neurosurgical Societies (WFNS) grading scheme is used 79 .…”

Automated pupillometry and the FOUR score — what is the diagnostic benefit in neurointensive care?

“…The minimum interval between assessments was 8 h. Nineteen of the patients (34%) achieved a favourable outcome (GOSE ≥ 5). The median GCS was 6 (IQR, 3-8; range, [3][4][5][6][7][8][9][10][11][12][13][14], and the median FOUR score was 7 (IQR, 4-11; range, 0-16). Assessments with a GCS of 3 corresponded to a median FOUR score of 4 (IQR, 4-5; range, 0-6); similarly, GCS 3-5 corresponded to a median FOUR score of 4 (IQR, 4-5; range, 0-10) ( Fig.…”

“…The validity of the FOUR score renders it a good predictor of patient outcome. Validity studies have assessed the FOUR score at a specific time point during ICU admission to define the best cut-off between favourable and unfavourable outcome, showing that the FOUR score compares favourably as a predictor [1,2,4,5].…”

FOUR score versus GCS in patients with traumatic brain injury in the prehospital setting

“…A recent study on the FOUR score overall showed that the FOUR score has a close relationship to in-hospital mortality and poor functional outcome in patients with impaired consciousness. This research also claims that there was insu cient evidence to determine whether performance was modi ed in different groups, and there was some suggestion that the assessment of brainstem re exes and respiratory patterns made less contribution than eye and motor scores [22].…”