Mar 26, 2012
– “Older adults have a 2.4-fold increase in the rate of cognitive decline after hospitalization, an increased risk that persisted after adjustment for severity of illness and length of hospital stay, according to a new study.”
– “As part of the longitudinal, population-based Chicago Health and Aging Project, researchers assessed changes in cognitive function among older people. They used a composite of cognitive tests that assessed episodic memory (immediate and delayed recall), executive function, and global cognition (Mini-Mental State Examination).”
– “…And perhaps we should be treating older people with cognitive impairment when they are hospitalized differently than we are now.”
- Results: During a mean of 9.3 years, 1,335 of 1,870 persons (71.4%) were hospitalized at least once. In a mixed-effects model adjusted for age, sex, race, and education, the global cognitive score declined a mean of 0.031 unit per year before the first hospitalization compared with 0.075 unit per year thereafter, a more than 2.4-fold increase. The posthospital acceleration in cognitive decline was also evident on measures of episodic memory (3.3-fold increase) and executive function (1.7-fold increase). The rate of cognitive decline after hospitalization was not related to the level of cognitive function at study entry (r = 0.01, p = 0.88) but was moderately correlated with rate of cognitive decline before hospitalization (r = 0.55, p = 0.021). More severe illness, longer hospital stay, and older age were each associated with faster cognitive decline after hospitalization but did not eliminate the effect of hospitalization.
- Conclusion: In old age, cognitive functioning tends to decline substantially after hospitalization even after controlling for illness severity and prehospital cognitive decline.