Fitter individuals are at the highest risk of death associated with delirium

Melanie Dani is a trainee in geriatric medicine in the North West Thames deanery. She is also completing a PhD at Imperial College London studying biomarkers in Alzheimer’s Disease, and has an interest in cognition and dementia.

It is well-recognised that delirium is associated with increased mortality. It’s less clear, though, whether this is the case across the spectrum of frailty. There is an idea that delirium might have bimodal outcomes – worse in frailer people, but may be protective in fitter individuals by highlighting an underlying problem early and (potentially) prompting earlier treatment.

While past studies have accounted for chronic diseases and acute illness severity, few have accounted for both. We wanted to see whether the associations of delirium with mortality remained so even after accounting for acute and chronic health factors, so we modelled both these together in a frailty index. This included 31 variables encompassing chronic disease, acute illness parameters, and functional status and was applied in a large cohort of acute medical older inpatients.