Title: Assessing recovery from delirium in older hospitalised people: optimisation and validation of the 4AT
Funder: Dunhill Medical Trust

Abstract: Introduction Delirium is a common (1 in 4 older hospital patients) and severe neuropsychiatric syndrome in which there is rapid deterioration in mental functioning. It is associated with multiple adverse outcomes [1, 2]. Delirium is mainly triggered by acute illness, surgery or drugs. Treatment involves addressing these triggers, and managing distress and agitation. Most delirium lasts 2-4 days but 20% of cases persist for weeks or longer [3, 4]. It is essential that recovery from delirium is assessed in hospital to inform ongoing treatment and discharge planning; notably delirium at hospital discharge is linked with poor outcomes [5]. Yet there are no validated clinical methods to assess delirium recovery [6]. The 4 “A”s test (4AT) is a widely used clinical test validated for delirium screening [7-9]. The 4AT is sometimes used for assessment of delirium recovery, but it has not been validated for this purpose. Aims To validate the 4AT as a means of assessing for delirium recovery. Methods This project will have two phases. Phase 1 objectives: to understand current clinical practice regarding assessment for delirium recovery through a web survey and an updated literature review; in N=400 of participants with repeated testing in our previous delirium studies to evaluate which short cognitive tests potentially provide information on recovery from delirium; to then select short cognitive tests additional to the 4AT as comparators; pilot study of 4AT plus cognitive tests in 30 patients. Phase 2 comprises two validation studies: (A) a study in Edinburgh of 150 older surgical (cardiac and hip fracture) and medical patients with delirium. We will do 2-4 assessments over 2 weeks comprising independent rater, blinded assessments of delirium reference standard (DSM-5 [10]) and 4AT plus additional cognitive tests; (B) a pragmatic study of 100 older inpatients (medical, surgical, other) with delirium in an established study in London [11]. Statistical analysis: (a) cross-sectional diagnostic accuracy using sensitivity, specificity, and positive and negative predictive values, and (b) longitudinal evaluation of responsiveness to change in delirium status using generalised linear mixed effects models. Potential impact This study fulfils a major unmet medical need: a pragmatic and validated method for repeated assessment of delirium recovery in routine clinical care. The 4AT is already established as a mainstream clinical tool. This study has the potential therefore to have a large impact because validation for longitudinal assessment for recovery would be a significant extension of existing use of this tool.

Lay abstract: Delirium or ‘acute confusional state’ is a condition where the mental functioning of people who are medically unwell or who are undergoing surgery gets worse over hours or days. People with delirium don’t think as clearly, can get very sleepy or agitated, and some also develop frightening hallucinations or delusions. Care involves treating the medical causes, and also managing any distress and agitation. Delirium is very common and affects 1 in 4 older people in hospital. Delirium mostly lasts for a few days but it may persist for weeks or months. It’s crucial staff know if a person is recovering from delirium, because this guides ongoing treatment and helps staff decide if a person is well enough to go home. There are many tests used to rate delirium but none have been tested for their ability to measure recovery from it. The 4 “A”s test or 4AT (www.the4AT.com) is used to test for delirium. It’s short and simple, and is widely used to test for delirium both in the UK and internationally. Some staff already use the 4AT to assess recovery from delirium - but nobody has ever done a study to test whether the 4AT really is suitable for this. We now want to do a study to see if 4AT works as a tool for assessing recovery from delirium. First we will survey staff and the literature to find out how recovery from delirium is being assessed just now. Then we will do a pilot study with 30 hospitalised older people with delirium (with the person’s consent or by legal proxy). These patients will get a standard delirium assessment, plus the 4AT and additional cognitive tests, up to 4 times over 2 weeks. This will help us to understand if the 4AT is enough, or whether more tests are needed. Then we’ll do a more formal study of 150 older hospitalised patients with delirium in Edinburgh, and another related study of 100 patients in London (who are already undergoing a study and will have to do no extra tests). If our study finds that 4AT is a suitable tool for repeated testing for delirium recovery, it should be easy to adopt it widely because many staff and institutions are already using it to find out if someone has delirium or not.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: GENERIC HEALTH RELEVANCE