The effectiveness of FOUR score versus GCS scale in predicting mortality and morbidity in traumatic brain injured patients in intensive care: A systematic review

Traumatic brain-injury (TBI) is one of the leading causes of death and disability worldwide. In intensive care, the Glasgow coma scale (GCS) is widely used to assess severity of brain injury. An alternative tool is the Full Outline of UnResponsiveness (FOUR) score which assesses stages of locked-in syndrome and brain herniation. The purpose of this study is to evaluate the effectiveness of both assessment tools in predicting mortality and morbidity in critically ill patients with TBI. Systematic review guided by the Joanna Briggs Institute (JBI) Manual for Evidence Synthesis (2021). A comprehensive database search was conducted for the period January 2005-September 2023. Searches repeated in February 2025. Primary research comparing FOUR with GCS, published in English, including adults aged 16 and over and patients with TBIs in intensive care were included. Studies were appraised using JBI critical appraisal tools. Data was narratively synthesised. Eleven studies were included. No study reported significant statistical differences between GCS and FOUR score in predicting mortality. Area under the curve and receiving operating characteristic curve values for both tools were rated good to excellent (Range 0.80-0.96) in predicting mortality. Morbidity was only reported in 6/11 studies. Neither tool appeared to effectively predict morbidity however, there was great variability in which and how morbidity outcomes were assessed. Both assessment tools perform similarly in predicting mortality and morbidity in TBI in intensive care. Further research to determine the additional clinical benefits of FOUR assessment in this population is recommended. The development of core morbidity outcome measures in patients with TBI is required to evaluate if these tools effectively predict morbidity. Effective prognostication may assist healthcare providers in managing resources as well as providing patients and families with realistic expectations of long-term recovery.