People with Parkinson’s disease are almost twice as likely to have delirium during hospital stays compared to others who are hospitalized but don’t have the disease, according to a study published March 15 in Age and Ageing.

Delirium isn’t often documented in people with Parkinson’s, though about two-third of people in the study experienced it, according to the report. The symptoms of delirium can sometimes be similar to Parkinson’s.

The team evaluated data from 121 people with Parkinson’s disease and 199 older adults without Parkinson’s who stayed at Newcastle University hospitals. Of them, 173 people had data on at least one of the three adverse outcomes recorded: dementia, institutionalization and death. The average age of participants was 77. 

People with Parkinson’s disease were more likely to have dementia when they were admitted to the hospital compared to those who didn’t have it. Of the people hospitalized, 66.9% of those with Parkinson’s had delirium compared to 38.7% adults without Parkinson’s disease.

In people with and without Parkinson’s disease, those with delirium had significantly lower survival likelihood in the year after they got out of the hospital. Delirium was significantly linked to a threefold higher chance of dying within a year of discharge in people who had Parkinson’s disease, the data showed.

Those who had delirium also had a higher likelihood of being institutionalized after leaving the hospital. In fact, 48.1% of the Parkinson’s patients who weren’t in care homes before they experienced delirium moved to facilities within a year of being discharged, compared with 5.9% of those without delirium and 16.3% of controls who experienced delirium.

People who didn’t have dementia when they went to the hospital had a higher chance of developing dementia a year later if they had delirium in the hospital compared to those who didn’t. 

Becky Jones, PhD, research communications manager at Parkinson’s UK, said the study “highlights the urgent need for better ways of measuring delirium in people with Parkinson’s, and being able to treat it sooner.”

These findings indicate that “missing signs of delirium in people with Parkinson’s can have serious consequences,” Jones said. 

“We have found that delirium can have a serious effect on the lives of people with Parkinson’s and their loved ones,” Rachael Lawson, PhD, study author and a Parkinson’s UK senior research fellow, said in a statement. Her group funded the study.