Background: Delirium is a frequent acute neuropsychiatric illness that affects attention, consciousness, and cognition.
 Objectives: The 4AT evaluation tool's validity and reliability in hospitalized non-ICU patients over 65 were assessed in this systematic study.
 Method: PRISMA guidelines and the PICO framework were used, and relevant research papers were found utilizing several databases (PubMed, Scopus, Web of Sciences, and ScienceDirect). The Mixed Methods Appraisal Tool was used to evaluate the study's quality.
 Results: 257 relevant publications were found, and only ten articles were selected based on inclusion criteria after the screening. Several studies were reported from various regions, including Asia, Europe, Canada, and Australia. Furthermore, studies found varying prevalence levels for 4AT and control groups, with the greatest for the 4AT group being 40.32%. Moreover, most research employed DSM-5 criteria, while some relied on CAM, DSM-4, and Psychiatric examination by qualified clinicians. Meanwhile, the sensitivity varied from 70% to 100%, and the specificity ranged from 71.6% to 99.2%. In contrast, other assessment tools, such as CAM and OBS, also demonstrated sensitivity and specificity. The main advantage was the time to complete the 4AT tool, which required 2-3 minutes, whereas the other tools took 3.6 and 12.46 minutes, respectively. The 4AT tool was a rapid, validated, easy patient assessment tool. In addition, it was found to improve delirium diagnosis.
 Conclusion: The tool has been found to have good sensitivity and specificity, and it may be completed quickly by non-specialists.