Hospitalized older adults may have increased risk of cognitive decline

Rush University Medical CenterMar 23 2012

A new study published in the March 21 issue of Neurology suggests that older adults who are hospitalized may have an increased risk of subsequent cognitive decline.

The study, conducted by researchers at the Rush Alzheimer's Disease Center and the Rush Institute for Healthy Aging, Rush University Medical Center, found that hospitalization of older adults was associated with increased memory and thinking problems.

"Our study is timely as the United States population continues to rapidly age and researchers try to identify factors that could decrease memory and thinking problems in older adults," said Robert S. Wilson, PhD, study author and neuropsychologist at Rush University Medical Center in Chicago. "Understanding a possible link to something as common as hospital stays is extremely important."

It is common for memory and thinking skills to decline slightly during the aging process. In the study, researchers found that overall cognitive function declined more than twice as fast after a first hospital stay, compared either to the previous rate before the hospital stay or to people who were not admitted to the hospital. On specific cognitive tests, the rate of decline after the first hospital stay was more than three times faster on a long-term memory test and 1.5 times faster on a complex attention test. The results stayed the same even after considering factors such as severe illness, longer hospital stay and older age.

While cognitive dysfunction has been identified as a complication of critical illnesses that may increase the chance of hospitalization, only 3 percent of hospitalizations involved critical illnesses in this particular study.

"Further research may help to develop strategies to prevent medical problems in older people that lead to hospital stays. It could also lead to changes in hospital inpatient and discharge policies," said Wilson.

The study involved 1,870 people over the age of 65 who lived in Chicago and were interviewed every three years for up to 12 years to test their memory and thinking skills. Of those, 1,335 people, or 71 percent, were hospitalized at least once during the study.

Study participants were residents of a geographically defined area that included approximately equal numbers of blacks and whites. The correlation of hospitalization with increased cognitive decline was similar in black and white persons.