Informal judgement of delirium status underestimates delirium prevalence: World Delirium Awareness Day point prevalence results from Ireland

Introduction
Delirium is an encephalopathy characterized by acute onset, fluctuation, and prominent deficits in attention and alertness, due to one or more physical disorders, interventions or medications. It is associated with increased mortality and morbidity, and with incidence and worsening of dementia; thus, delirium prevention and timely detection and appropriate management are crucial.

Objective
This study aimed to determine delirium prevalence in Irish clinical sites.

Methods
The overall study was an observational, cohort study of the point prevalence of delirium (and current delirium practice) in multiple clinical sites on a single day (i.e. World Delirium Awareness Day, March 2023). In this study, the point prevalence of delirium is reported in Irish sites.

Results
In total, 132 wards from 15 hospitals across Ireland participated in this study, including general medical, surgical and specialised wards, and some long-term care and rehabilitation wards. Overall, 27% of patients on wards which reported using a formal tool had not been assessed for delirium. Delirium prevalence, using a formal assessment tool, was 15.9% overall, with the highest rate in geriatric wards (20.5%). However, on wards where ‘personal judgment’ to detect delirium was utilized, the prevalence rate was 11.5%, implying that delirium may have been under-detected on these wards.

Conclusions
Delirium screening can quickly rule out delirium or lead to more formal assessment where screening is positive or equivocal. Delirium is prevalent in Irish hospitals and appears to be under-detected unless a formal screening tool is used; equally, delirium screening is not universally applied on wards reporting that they use a formal tool. Together, this indicates that delirium is still under-diagnosed in Irish hospitals.