Cognitive decline after elective and nonelective hospitalizations in older adults.

Objective: To determine whether emergent and urgent (nonelective) hospitalizations are associated with faster acceleration of cognitive decline compared to elective hospitalizations, accounting for prehospital decline.

Methods: Data came from the Rush Memory and Aging Project, a prospective cohort study of community-dwelling older persons without baseline dementia. Annual measures of cognition via a battery of 19 tests were linked to 1999 to 2010 Medicare claims records.

Results: Of 777 participants, 460 (59.2%) were hospitalized over a mean of 5.0 (SD = 2.6) years; 222 (28.6%) had at least one elective and 418 (53.8%) at least one nonelective hospitalization. Mixed-effects regression models estimated change in global cognition before and after each type of hospitalization compared to no hospitalization, adjusted for age, sex, education, medical conditions, length of stay, surgery, intensive care unit, and comorbidities. Persons who were not hospitalized had a mean loss of 0.051 unit global cognition per year. In comparison, there was no significant difference in rate of decline before (0.044 unit per year) or after (0.048 unit per year) elective hospitalizations. In contrast, decline before nonelective hospitalization was faster (0.076 unit per year; estimate = -0.024, SE = 0.011, = 0.032), and accelerated by 0.036 unit (SE = 0.005, < 0.001) to mean loss of 0.112 unit per year after nonelective hospitalizations, more than doubling the rate in those not hospitalized.

Conclusions: Nonelective hospitalizations are related to more dramatic acceleration in cognitive decline compared to elective hospitalizations, even after accounting for prehospital decline. These findings may inform which hospital admissions pose the greatest risk to the cognitive health of older adults.