Infection increases mortality risk among patients with dementia, new research suggests. A large, registry-based cohort study showed that
“This is the first study to our knowledge to show that increased mortality is observed across all infection types in people with dementia and that increased mortality is seen both short and long term,” said coinvestigator Janet Janbek, a PhD student at the Danish Dementia Research Center, Rigshospitalet, University of Copenhagen.
The findings were presented at the virtual annual meeting of the Alzheimer’s Association International Conference.
Large Danish cohort
The investigators analyzed data from Danish national health registries for nearly 1.5 million individuals aged 65 years and older who had visited the hospital with an infection. There were 575,260 deaths during more than 12.7 million person-years of follow-up.
Patients with dementia who also had a hospital visit for infection died at a 6.5 times higher rate than participants without dementia or an infection. Those with either dementia alone or infection-related contacts alone had a threefold increased rate of death.
The mortality rate was highest within the first 30 days following the hospital visit for infection. However, the rate remained elevated for 10 years after the initial infection-related hospital visit.
Mortality rates from all infections, including major infections, such as sepsis, down to minor ear infections were elevated in patients with dementia, compared with people who did not have dementia or an infection-related hospital visit.
Ms. Janbek said there are several possible explanations for the association of infection and increased mortality risk in those with dementia. “After a hospital contact with a severe infection, people with dementia may become more reliant on external care, become more frail, and have declined functional levels, which might explain the observed association.”
It might also be that patients with dementia have more severe infections than those without dementia at the time of hospital contact, possibly because of delayed diagnosis, which could explain the higher mortality rates, said Ms. Janbek.
“It is also plausible that infections play a role in worsening dementia and subsequently lead to increased mortality,” she noted.
“Clinicians and health care personnel need to pay closer attention to infections of all types in people with dementia, and steps toward better clinical management and improved posthospital care need to be explored and undertaken. We need to identify possible preventive measures and targeted interventions in people with dementia and infections,” Ms. Janbek said.
Commenting on the study,, director of scientific engagement for the Alzheimer’s Association, said it presents “an interesting observation.” However, “we can’t make any direct assumptions from this research per se about infections and dementia and whether they are causative in any way,” noted Dr. Edelmayer, who was not involved with the study.
Instead, the study highlighted the importance of “taking care of our overall health and making sure that individuals that might be vulnerable to infection, like those who are already living with dementia, are getting the best care possible,” she said.
Ms. Janbek and Dr. Edelmayer have reported no relevant financial relationships.
A version of this article originally appeared on.