Hospital Stays Raise Dementia Risk
Older People Who Have Been Hospitalized More Likely to Have Dementia, Mental Decline
WebMD News Archive
Feb. 23, 2010 -- Seniors who have been hospitalized may be more likely to
develop dementia and mental decline than seniors who have not
been hospitalized, a new study shows.
William J. Ehlenbach, MD, MSc, of the University of Washington in Seattle,
and colleagues analyzed data from a study on mental function of older adults.
They looked to see whether a history of hospitalization was associated with
mental decline and dementia.
The researchers found that older patients who had been hospitalized for a
non-critical illness had a 40% higher risk of dementia. Follow-up mental test
scores were also lower in participants who had been hospitalized compared to
those who had not.
"The mechanism of this association is uncertain," the researchers write.
"Hospitalization may be a marker for cognitive decline or dementia that has not
been diagnosed. [But] these results also could suggest that factors associated
with acute illness, and to a greater degree with critical illness, may be
causally related to cognitive decline."
Dementia and Aging
The researchers examined data on 2,929 people 65 and older who were part of
a Seattle-area study on aging and dementia from 1994 to 2007. None of the study
participants had dementia at the start of the study or were living in a nursing
Mental abilities were tested every two years.
After an average follow-up of six years, 1,601 patients had not been
hospitalized, 1,287 had been hospitalized for non-critical illness, and 41 had
been hospitalized for critical illness.
Researchers found 146 cases of dementia among those not hospitalized. Among
those hospitalized for non-critical illness, 228 dementia cases were found.
Five cases of dementia were found among people hospitalized for critical
Seniors hospitalized for a critical illness, such as shock or needing a
mechanical ventilator to breathe, were also found to be at higher risk of
dementia, but this may have been a chance finding due to the small number of
participants hospitalized for critical illness.
The researchers write that "an acute or critical illness may cause an abrupt
loss of cognitive function rather than steepening the slope of decline or
simply being a marker of cognitive decline."
They add that more studies are needed to look into the relationship between
hospitalization and mental decline in seniors.