Inter-rater reliability of the Full Outline of UnResponsiveness score and the Glasgow Coma Scale in critically ill patients: a prospective observational study

Stephan Rüegg,Michael Fischer,Franziska Tschan,Stephan C Marsch,Adam Czaplinski,Angelika Lehmann,Patrick R Hunziker,Monika Strohmeier

doi:10.1186/cc8963

Abstract

IntroductionThe Glasgow Coma Scale (GCS) is the most widely used scoring system for comatose patients in intensive care. Limitations of the GCS include the impossibility to assess the verbal score in intubated or aphasic patients, and an inconsistent inter-rater reliability. The FOUR (Full Outline of UnResponsiveness) score, a new coma scale not reliant on verbal response, was recently proposed. The aim of the present study was to compare the inter-rater reliability of the GCS and the FOUR score among unselected patients in general critical care. A further aim was to compare the inter-rater reliability of neurologists with that of intensive care unit (ICU) staff.MethodsIn this prospective observational study, scoring of GCS and FOUR score was performed by neurologists and ICU staff on 267 consecutive patients admitted to intensive care.ResultsIn a total of 437 pair wise ratings the exact inter-rater agreement for the GCS was 71%, and for the FOUR score 82% (P = 0.0016); the inter-rater agreement within a range of ± 1 score point for the GCS was 90%, and for the FOUR score 92% (P = ns.). The exact inter-rater agreement among neurologists was superior to that among ICU staff for the FOUR score (87% vs. 79%, P = 0.04) but not for the GCS (73% vs. 73%). Neurologists and ICU staff did not significantly differ in the inter-rater agreement within a range of ± 1 score point for both GCS (88% vs. 93%) and the FOUR score (91% vs. 88%).ConclusionsThe FOUR score performed better than the GCS for exact inter-rater agreement, but not for the clinically more relevant agreement within the range of ± 1 score point. Though neurologists outperformed ICU staff with regard to exact inter-rater agreement, the inter-rater agreement of ICU staff within the clinically more relevant range of ± 1 score point equalled that of the neurologists. The small advantage in inter-rater reliability of the FOUR score is most likely insufficient to replace the GCS, a score with a long tradition in intensive care.

Highlights

The Glasgow Coma Scale (GCS) is the most widely used scoring system for comatose patients in intensive care
The exact inter-rater agreement among neurologists was superior to that among intensive care unit (ICU) staff for the Full Outline of UnResponsiveness (FOUR) score (87% vs. 79%, P = 0.04) but not for the GCS (73% vs. 73%)
Though neurologists outperformed ICU staff with regard to exact inter-rater agreement, the inter-rater agreement of ICU staff within the clinically more relevant range of ± 1 score point equalled that of the neurologists

Summary

Introduction

The Glasgow Coma Scale (GCS) is the most widely used scoring system for comatose patients in intensive care. In the ICU, a variety of conditions such as intubation, sedation, or delirium preclude a reliable assessment of a verbal response and, the FOUR score is an attractive tool. Before this new score can be recommended for routine use in the ICU, the following limitations should be addressed: so far the FOUR score has not been validated in critically ill patients outside of the Mayo Clinic; so far the FOUR score has not been validated in sedated patients; and so far the FOUR score has only been validated by dedicated staff in neuro-ICUs. before this new score can be recommended for routine use in the ICU, the following limitations should be addressed: so far the FOUR score has not been validated in critically ill patients outside of the Mayo Clinic; so far the FOUR score has not been validated in sedated patients; and so far the FOUR score has only been validated by dedicated staff in neuro-ICUs

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