Cognitive Fluctuations in Delirium

This study aims to better understand cognitive fluctuation in older people living in residential age care and how it relates to diagnosis of delirium and dementia. The study will first estimate the prevalence of delirium in older adults in three rural residential care facilities (Study 1). It will then compare the occurrence and characteristics of cognitive fluctuations in people with delirium with people with dementia but no delirium (Study 2). Consent will be obtained for both Study 1 and Study 2 at the outset. Study 1 includes collection of data routinely collected by the residential aged facility for all older adults who have consented or for whom there is appropriate proxy consent. Following this, on a selected day 4AT will be administered. 4AT is an evidence-based bedside tool for rapid delirium screening that takes about 2 minutes to administer, Study 2 will prospectively identify participants who may have delirium from the group of participants who have previously consented or have proxy consent. Following screening with 4AT a participant with delirium and a participant with dementia but no delirium will be assessed for arousal levels using Modified Richmond Agitation Sedation Scale (mRASS) every hour. mRASS is an observational instrument derived from the Richmond Agitation Sedation Scale that measures the states of arousal, from unarousable (-5) to combative (+4). If arousal level allows for attention assessment, then participants' attention will be assessed hourly (where permitting) using DelApp. Hourly assessments will occur over two consecutive days from 9 am to 6 pm to minimise impact on sleep.