Critical Illnesses Raise Dementia Risk

(February 24, 2010) - A critical illness can increase your odds of developing dementia. (Read about "Dementia") Older patients hospitalized for acute care or a critical illness are more likely to experience cognitive decline compared to older adults who are not hospitalized, according to a study in the Journal of the American Medical Association.

A large proportion of patients who are hospitalized for acute care or care of a critical illness are older adults. Some studies have suggested that many survivors of critical illness experience long-term cognitive impairment, but these studies did not measure cognitive function before a critical illness, according to background information in the article.

Researchers analyzed data from a study that was conducting cognitive testing on older adults, and examined administrative data from hospitalizations to determine whether hospitalizations for acute illness or critical illness were associated with cognitive decline and dementia. The study included data from 1994 through 2007 on 2,929 individuals, 65 years old and older without dementia at the beginning of the study. Cognition was measured with the Cognitive Abilities Screening Instrument (CASI) every 2 years at follow-up visits, and those with scores below a certain point underwent a clinical examination for dementia.

The researchers found that patients who had a hospitalization for an acute care or critical illness had lower CASI scores at follow-up compared to those who were not hospitalized. Patients hospitalized for a critical illness also had a higher risk of dementia.

"These results could suggest that factors associated with acute illness, and to a greater degree with critical illness, may be causally related to cognitive decline," the authors write.