Feasibility of the Four 'A's Test (4AT) Delirium Screening Tool in Older Adults Presenting to the Emergency...

Delirium is a common, serious, and frequently underdiagnosed condition in older adults presenting to the emergency department (ED). The Four 'A's Test (4AT) is a brief, validated delirium screening tool requiring no specialist training or equipment, making it potentially well-suited to the fast-paced ED environment. However, evidence on its feasibility in this setting remains limited and has not been systematically synthesised. This rapid systematic review aimed to evaluate the feasibility of the 4AT, including completion time, completion rates, staff acceptability, and implementation barriers and facilitators, in EDs for adults aged 65 years and older. A rapid systematic review was conducted in accordance with PRISMA 2020 guidelines and prospectively registered on PROSPERO (CRD420261370525). PubMed, MEDLINE via Ovid, and EMBASE via Ovid were searched from January 2011 to April 2026. Two reviewers independently screened titles, abstracts, and full texts, with conflicts resolved by discussion. Primary studies reporting feasibility outcomes for the 4AT in an ED setting in adults aged ≥65 were included. Data were extracted using a standardised form and methodological quality was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist appropriate to each study design. Findings were synthesised narratively. A total of 195 records were identified across PubMed, MEDLINE, and EMBASE. Following removal of 98 duplicates, 97 unique records were screened at title and abstract stage, of which 23 were retrieved for full-text review. Six studies met the inclusion criteria and were included in the final synthesis (UK n = 3, Spain n = 1, Norway n = 1, Netherlands n = 1). The available evidence suggests that the 4AT is feasible across emergency care settings, with short completion times, high acceptability among healthcare professionals, and minimal training requirements. Implementation success was influenced primarily by organisational factors, with education, electronic integration, and workflow support facilitating uptake, while time pressures and competing clinical demands remained key barriers. The available evidence suggests that the 4AT is a feasible delirium screening tool for older adults presenting to EDs, demonstrating rapid administration, minimal training requirements, and generally positive staff acceptability. However, successful implementation appears to depend on organisational factors, including staff education, workflow integration, and clear allocation of screening responsibilities. These findings support consideration of the 4AT within ED delirium screening pathways, while highlighting the need for further research on implementation strategies and long-term clinical outcomes.