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Recurrent delirium over 12 months predicts dementia: results of the Delirium and Cognitive Impact in Dementia (DECIDE) study

Lookup NU author(s): Dr Sarah Richardson, Dr Daniel Davis, Professor Bloss Stephan, Professor Dame Louise Robinson, Professor Carol Brayne, Professor John-Paul TaylorORCiD, Emeritus Professor Stuart ParkerORCiD, Dr Louise Allan



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Background: Delirium is common, distressing and associated with poor outcomes. Previous studies investigating the impact of delirium on cognitive outcomes have been limited by incomplete ascertainment of baseline cognition or lack of prospective delirium assessments. This study quantified the association between delirium and cognitive function over time by prospectively ascertaining delirium in a cohort aged ≥ 65 years in whom baseline cognition had previously been established.MethodsFor 12 months, we assessed participants from the Cognitive Function and Ageing Study II-Newcastle for delirium daily during hospital admissions. At 1-year, we assessed cognitive decline and dementia in those with and without delirium. We evaluated the effect of delirium (including its duration and number of episodes) on cognitive function over time, independently of baseline cognition and illness severity.ResultsEighty two of 205 participants recruited developed delirium in hospital (40%). One-year outcome data were available for 173 participants: 18 had a new dementia diagnosis, 38 had died. Delirium was associated with cognitive decline (−1.8 Mini-Mental State Examination points [95% CI –3.5 to –0.2]) and an increased risk of new dementia diagnosis at follow up (OR 8.8 [95% CI 1.9–41.4]). More than one episode and more days with delirium (>5 days) were associated with worse cognitive outcomes.ConclusionsDelirium increases risk of future cognitive decline and dementia, independent of illness severity and baseline cognition, with more episodes associated with worse cognitive outcomes. Given that delirium has been shown to be preventable in some cases, we propose that delirium is a potentially modifiable risk factor for dementia.

Publication metadata

Author(s): Richardson SJ, Davis DHJ, Stephan BCM, Robinson L, Brayne C, Barnes LE, Taylor J-P, Parker SG, Allan LM

Publication type: Article

Publication status: Published

Journal: Age and Ageing

Year: 2021

Volume: 50

Issue: 3

Pages: 914-920

Print publication date: 01/05/2021

Online publication date: 16/12/2020

Acceptance date: 27/09/2020

Date deposited: 14/02/2021

ISSN (print): 0002-0729

ISSN (electronic): 1468-2834

Publisher: Oxford University Press


DOI: 10.1093/ageing/afaa244


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Funder referenceFunder name
... and the Alzheimer’s Society [grant number 294].
Clinical Research Fellowship from the Alzheimer’s Society [grant number 239 (AS-CTF-14-001)] awarded to S.J.R.
FAS II-Newcastle is funded by the UK Medical Research Council [grant number G0601022] ...