The use of anticholinergic drugs in the elderly has been associated to an increased frequency of delirium. There are different scales for estimating the anticholinergic burden, such as the Anticholinergic Drug Scale (ADS), Anticholinergic Risk Scale (ARS), and Anticholinergic Cognitive Burden (ACB). The aim of the study is to establish the relationship between anticholinergic burden measured by ADS, ARS, and ACB scales and incident or prevalent delirium.
An ambispective observational study was conducted for 76 days in the acute geriatric unit of a tertiary hospital. All patients over 80 years-old were included, except re-admissions or those subjected to palliative care. The data collected included sex, age, chronic medication and any recent changes, recent drugs prescribed prior to an episode of delirium, chronic kidney disease, diabetes mellitus, dementia, visual and auditory impairment, and their combination as sensory impairment, previous falls, stroke, brain tumour, and incident and prevalent delirium.
A total of 72 patients were included. Incident delirium was detected in 8.1% of the patients, and prevalent delirium in 40.9%. A statistically significant association was established between anticholinergic drugs and the incident delirium measured by the ARS scale (P=.017). None of the scales was able to establish a significant association with prevalent delirium.
The ARS scale was related to new episodes of delirium. All scales were insufficient when it came to establishing an association with prevalent delirium.