A validated 4-item bedside tool for detecting delirium. Takes under 2 minutes. No training required.
Instructions: Assess each of the 4 items and select the most appropriate response. This tool is designed to be used at the bedside by any healthcare professional. It does not require cognitive testing training and can be used even if the patient is drowsy or uncooperative.
The 4AT is a rapid screening instrument designed for the initial assessment of delirium and cognitive impairment. It was developed by MacLullich and colleagues at the University of Edinburgh and has been extensively validated in hospital and community settings.
Key advantages of the 4AT: it takes less than 2 minutes to complete, requires no special training, can be administered even to drowsy or uncooperative patients, and has good sensitivity and specificity for detecting delirium.
The 4AT assesses four domains: alertness (hyper or hypoactive changes), abbreviated cognition (AMT4), attention (months backwards), and acute change or fluctuation.
Source: Bellelli G et al. Age and Ageing 2014;43:496-502. Free to use — the4at.com
Delirium is almost always caused by an underlying medical condition. Common triggers include:
Infection: Urinary tract infection (most common in older adults), pneumonia, cellulitis, sepsis.
Medications: Anticholinergics, opioids, benzodiazepines, steroids, polypharmacy. Always review the medication list.
Metabolic: Dehydration, electrolyte disturbance (sodium, calcium), renal failure, hepatic failure, hypoglycaemia, thyroid dysfunction.
Neurological: Stroke, seizures, intracranial haemorrhage, meningitis.
Other: Pain (especially undertreated), constipation, urinary retention, surgery/anaesthesia, alcohol withdrawal, sleep deprivation, sensory deprivation (missing glasses/hearing aids).
The mnemonic PINCH ME can help: Pain, Infection, Nutrition, Constipation, Hydration, Medication, Environment.
Distinguishing delirium from dementia is critical because delirium is usually reversible when the underlying cause is treated, while dementia is chronic and progressive. Key differences:
Onset: Delirium — acute (hours to days). Dementia — gradual (months to years).
Course: Delirium — fluctuating, often worse at night. Dementia — stable day to day.
Attention: Delirium — markedly impaired. Dementia — relatively preserved until late stages.
Alertness: Delirium — often altered (drowsy or agitated). Dementia — usually normal.
Important: Delirium and dementia can coexist. People with dementia are at much higher risk of developing delirium. A sudden change in someone with known dementia should always prompt a delirium screen.
Use the GPCOG to screen for dementia in a non-acute setting.