How to Cite: Amirtharaj, A. D., Lazarus, E. R., & Alzaabi, O. (2022). Assessing validity and reliability of glasgow coma scale and full outline of unresponsiveness score: A systematic review. International Journal of Health Sciences, 6(S2), 12293–12306. https://doi.org/10.53730/ijhs.v6nS2.8259 International Journal of Health Sciences ISSN 2550-6978 E-ISSN 2550-696X © 2022. Manuscript submitted: 09 March 2022, Manuscript revised: 18 April 2022, Accepted for publication: 27 May 2022 12293 Assessing validity and reliability of glasgow coma scale and full outline of unresponsiveness score: A systematic review Ms Anandhi Deva Amirtharaj RNRM, MSN, PhD Scholar, Lecturer, Sultan Qaboos University, College of Nursing, Sultanate of Oman Corresponding author email: anuamirtharaj@gmail.com Dr. Eilean Rathinasamy Lazarus RNRM, MSN, PhD, Assistant Professor, College of Nursing, Sultan Qaboos University, Sultanate of Oman Email: eileansrmc@gmail.com Dr. Omar Alzaabi PhD, MANP, DN (Nurse Practitioner, University of Melbourne, Australia), RN, Assistant Professor, College of Nursing, Sultan Qaboos University Muscat, Sultanate of Oman Email: alzaabi@squ.edu.om Abstract---Background: Monitoring accurately the patient’s level of consciousness is vital to the management and prognosis. Glasgow coma scale (GCS) the gold standard tool is associated with the discrepancy in scoring eye component and the non-usability of verbal component. The full outline of unresponsiveness (FOUR) score a recently validated tool surpasses the deficits of the GCS tool, examined for its accuracy in assessment, and predicting the outcomes of patients with altered level of consciousness. Aim: To evaluate the predictive value of the GCS and FOUR score tool in relation to the outcomes among patients in altered level of consciousness. Design: A systematic review. Data sources: The MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane Central Register of Controlled Trials (Cochrane Library), EMBASE, PsycINFO and Web of Science were searched “between” 2011 – 2021 and presented using PRISMA. Review methods: Research studies, which compared the GCS and FOUR score in predicting the outcome of patients with altered level of consciousness, were included. Results: 23 studies, which compared the GCS and FOUR score, were included in this review based on the inclusion criteria. Conclusion: 23 studies included in the review showed that FOUR score could be replaceable