Association of hospitalization with long-term cognitive and brain MRI changes in the ARIC cohort

Objective: To determine whether hospitalization is associated with subsequent cognitive decline or changes on brain MRI in a community-based cohort. Methods: Baseline and follow-up cognitive testing (n 2,386) and MRI scans with standardized assessments (n 885) were available from a subset of white and black participants in the Atherosclerosis Risk in Communities study. Cognitive tests included the Delayed Word Recall Test (DWRT), Digit Symbol Substitution Test (DSST), and Word Fluency Test (WFT). Hospitalization characteristics were determined using ICD-9 codes. Regression models adjusted for demographics, education, comorbidities, and APOE ε4 were used to estimate the independent association of hospitalization with changes in cognition or neuroimaging. Results: Over a mean 14.1 years between visits, 1,266 participants (53.1%) were hospitalized. Hospitalization compared with no hospitalization was associated with greater decline in DSST scores (1.25 points greater decline, p < 0.001) but no difference in DWRT or WFT score change. Each additional hospitalization, as well as a critical illness vs noncritical illness hospitalization, was associated with greater decline in DSST scores. A subset of participants (n 885) underwent MRI scans separated by 10.5 years. Hospitalization (n 392) compared with no hospitalization was associated with a 57% higher odds of increasing ventricular size at follow-up. Each additional hospitalization, as well as having a critical illness vs noncritical illness hospitalization, and having a hospitalization with major surgery vs no surgery was associated with greater odds of increased ventricular size. Conclusions: Cognitive decline and neuroimaging changes may occur after hospitalization, independent of baseline demographics and comorbidities.