A single episode of delirium in hospitalised older adults is a significant risk factor for other serious health complications including fractures, stroke and sepsis, new research shows.

Delirium, often triggered by infection, surgery, pain, dehydration or medication, affects up to one in four older adults during a hospital stay. However, many of its long‑term health impacts have not been fully understood.

In a large-scale study conducted by the University of Queensland, researchers analysed data from nearly 30,000 patients and hospital records over a period of up to 26 years to assess long-term clinical consequences of in-hospital delirium.

“We found delirium was associated with a higher risk of 12 adverse outcomes, independent of frailty and pre-existing dementia, which shows it is a warning of longer-term vulnerability,” said Dr David Ward from UQ’s Centre for Health Services Research.

An episode of delirium in hospital doubled the risk of falls and urinary incontinence, and there was a 50 to 70% increased risk of pneumonia, faecal incontinence, fractures, stroke, hip fracture, sepsis, acute kidney injury, and pressure injury.

There was also a 20 to 30% higher risk for gastrointestinal bleeding and heart failure.

“These are very strong associations that highlight delirium as a red flag for multisystem vulnerability, and we hope these findings will help guide follow-up care and prevention strategies,” said Dr Ward.

Research showed up to half of all delirium cases that develop in hospital could be prevented through better care practices.  

Episodes of delirium were often thought of as a short-lived complication, but the study showed a persistently elevated risk of adverse health outcomes even after the episode subsides, said lead author Dr Markus Haapanen from the University of Helsinki, who undertook a fellowship at UQ for the study.

“Identifying and managing delirium while patients are in hospital is often the focus of care, but these results suggest a need to extend treatment and care after a patient is discharged.

“Delirium prevention, treatments and structured follow-up for patients recovering from delirium represent opportunities for improving care and outcomes beyond hospitalisation.

“This research also opens the door for future studies to measure longer-term health outcomes following a delirium episode.”

The research was published in The Lancet Healthy Longevity.