Hospital stays can age the elderly

Modern hospitals can fix a multitude of ailments. But for older patients, hospitalization may result in a downward slide in one important respect: cognitive function.

That's the finding of a new 12-year study in the journal Neurology, in which researchers interviewed 1,870 seniors periodically to gauge their thinking skills and memory.

Everyone slows down a bit with age, mentally speaking. But patients who were hospitalized during the study slowed down much faster, on average. Their average "global cognition score" decreased at a rate that was 2.4 times greater than the rate of decline for those who were not hospitalized.

Certain other factors also were linked to a faster mental decline, among them older age and severity of illness. But the apparent impact of hospitalization remained statistically significant even after those factors were taken into account. In other words, there seems to be some consequence of hospitalization itself, regardless of how sick the patient is to begin with, said Robert S. Wilson, the study's lead author and a neuropsychologist at Rush University Medical Center in Chicago.

"After hospitalization, on average, people's rates of cognitive decline were the equivalent of being more than 10 years older," Wilson said.

The study did not reveal what might be causing the accelerated decline. But Wilson said the answer is likely to have multiple elements, such as complications from surgery, the impact of medications, and simple inactivity.

"If you're in the hospital for a week or two or more, you're usually pretty physically inactive," Wilson said. "You may be pretty mentally inactive as well. That might not be a good thing."

The switch to an unfamiliar environment may also play a role. There are patients who function fairly well at home, where they know where everything is, but the switch to a hospital setting may "unmask cognitive symptoms in vulnerable older persons," the authors wrote. Even after returning home, such patients may not regain their prior level of function, Wilson said.

Further research could suggest strategies for better hospital care to keep patients sharp, the authors wrote. Or better yet, improvements in primary care so hospitalization is unnecessary.

- Tom Avril