About Alasdair MacLullich
I am a geriatrician and delirium researcher based in Edinburgh. My work centres on the recognition, assessment and care of people with delirium, alongside acute geriatric medicine and orthogeriatrics.
My work
I am Professor of Geriatric Medicine at the University of Edinburgh and work clinically in acute geriatric medicine and acute orthogeriatrics at the Royal Infirmary of Edinburgh. Read more about my delirium and geriatric medicine research.
Alongside clinical and academic work, I am Editor-in-Chief of Delirium and Chair of the Scottish Hip Fracture Audit. I co-founded the European Delirium Association.
I originally designed the 4AT delirium assessment tool with Tracy Ryan and Helen Cash in 2011, and remain responsible for its updates.
This site links to information for patients and families, clinical tools, education, research, publishing and public awareness. Start with the delirium overview to find the relevant resource.
The 4AT in use
The 4AT is a brief bedside assessment designed to help healthcare professionals recognise possible delirium and cognitive impairment. NICE recommends it for assessment when indicators of delirium are identified in hospital or long-term care, except in critical care or the recovery room after surgery. SIGN recommends it to identify probable delirium in emergency and acute hospital settings. It is free to use, needs no registration and is available in more than 20 languages.
A 2021 systematic review and meta-analysis of 17 studies, comprising 3,702 observations, estimated pooled sensitivity and specificity of 0.88. In a 2019 multicentre study, 785 analysable acute medical patients received an independent reference assessment and were randomised to assessment with either the 4AT or CAM. Sensitivity and specificity were 76% and 94% for the 4AT, and 40% and 100% for the CAM.
In a 2025 national Scottish registry study, 16,476 (91%) of 18,040 people presenting with hip fracture received a 4AT assessment.
Use the official 4AT, work through clinical cases, or read the free practical manual. The research page gives further findings and links to the published evidence.
Profiles
These links provide institutional details, publications and researcher identifiers.
Profile links checked 4 September 2026.
This website
This is my independent professional website. It brings together work that is otherwise spread across separate organisations, publications and websites. Each linked website has its own purpose and editorial responsibility.
This is not an official website of the University of Edinburgh, NHS, Delirium journal, European Delirium Association, Scottish Hip Fracture Audit or iDelirium.