Cognitive decline after hospitalization in a
community population of older persons
R.S. Wilson, PhD
L.E. Hebert, ScD
P.A. Scherr, ScD, PhD
X. Dong, MD
S.E. Leurgens, PhD
D.A. Evans, MD
Objective: To test the hypothesis that hospitalization in old age is associated with subsequent
Methods: As part of a longitudinal population-based cohort study, 1,870 older residents of an
set of brief cognitive tests from which measures of global cognition, episodic memory, and exec-
utive function were derived. Information about hospitalization during the observation period was
obtained from Medicare records.
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 exec-
utive function (1.7-fold increase). The rate of cognitive decline after hospitalization was not re-
lated 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
Cognitive decline in old age is common and is associated with increased risk of disability,
dementia, and death. With the aging of the US population, this problem is expected to increase
in the coming decades, underscoring the need to identify factors contributing to cognitive
decline and strategies to reduce its impact. One common occurrence in old age that may be
related to cognitive decline is hospitalization. Two observations suggest an association. First,
hospitalization of older persons increases risk of loss of independence in daily living activi-
ties,1–3and this effect has been associated with impairment in cognitive functioning.4–8Second,
some common medical conditions, such as diabetes9,10and chronic obstructive pulmonary
disease,11,12and general indicators of physical health, such as frailty13,14and body mass in-
dex,15,16have been associated with late life cognitive decline. However, few studies have exam-
ined the relationship between hospitalization and change in cognitive function,17,18and their
ability to reliably estimate the association has been limited by insufficient longitudinal cogni-
tive data before and after hospitalization.
In the present study, we used data from the Chicago Health and Aging Project19to test the
hypothesis that hospitalization of older people is associated with subsequent cognitive decline.
Participants are 1,870 older residents of a geographically defined neighborhood in Chicago,
From the Rush Alzheimer’s Disease Center (R.S.W., S.E.L.), Rush Institute for Health Aging (L.E.H., P.A.S., X.D., D.A.E.), and Departments of
Neurological Sciences (R.S.W., S.E.L.), Behavioral Sciences (R.S.W.), and Internal Medicine (L.E.H., X.D., D.A.E.), Rush University Medical
Center, Chicago, IL.
Study funding: This research was supported by NIH/NIA grant R01-AG11101. The funding organization had no role in the design or conduct of the
study; collection, management, analysis, or interpretation of the data; or preparation, review, or approval of the manuscript.
Disclosure: Author disclosures are provided at the end of the article.
Correspondence & reprint
requests to Dr. Wilson:
Copyright © 2012 by AAN Enterprises, Inc.
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