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

Abstract

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.

Figure 1. Flow diagram

Patients included and excluded for analysis of cognitive and brain MRI changes in the Atherosclerosis Risk in Communities study.

Figure 2. Adjusted decline in cognitive test scores by number of noncritical illness hospitalizations

Adjusted decline in test scores for participants by number of hospitalizations, compared to the reference group of test score decline in participants with no hospitalizations. A (+) value for decline indicates that test scores worsened between baseline and follow-up, while a (−) value for decline indicates that test scores improved between baseline and follow-up. *Above each bar indicates a p value <0.05 for the comparison of cognitive decline for that particular number of hospitalizations compared to the reference of no hospitalizations. Overall p value refers to the overall association between each additional hospitalization and decline in individual test score.