Trajectories of cognitive performance in the six months after hospitalization with COVID-19 among community-dwelling older adults

BACKGROUND: Older adults are vulnerable to post-COVID-19 cognitive impairment (CI). This study aimed to characterize cognitive trajectories among older adults in the six months after hospitalization with COVID-19 and identify associated factors. METHODS: This prospective longitudinal cohort study included 311 community-dwelling adults age ≥60 years hospitalized with COVID-19 and enrolled in the VALIANT (COVID-19 in Older Adults: A Longitudinal Assessment) study between June 2020-June 2021. Cognitive performance was assessed using the Montreal Cognitive Assessment 5-minute protocol during hospitalization and at one, three, and six months post-discharge. Sociodemographic and clinical data were collected via baseline interviews and the electronic health record. Cognitive trajectories and their associated factors were identified using discrete mixture models and multinomial logistic regression. RESULTS: Mean age was 71.4 ± 8.4 years (54.6% women, 3.7% with documented evidence of pre-admission CI, 41% with in-hospital CI). Three cognitive trajectories were identified at six months post-discharge: persistent moderate impairment (14.1%), borderline impairment (47.5%), and no impairment (38.4%). Factors associated with membership in persistent moderate or borderline impairment trajectories, relative to the no impairment trajectory, were in-hospital cognitive performance, delirium, hearing impairment, and multimorbidity. Pre-admission CI perfectly predicted membership in the no impairment trajectory (i.e., zero participants in the no impairment trajectory had pre-admission CI). CONCLUSIONS: Distinct cognitive trajectories of persistent moderate impairment, borderline impairment, and no impairment emerged among older adults during the six months after hospitalization for COVID-19. Trajectory membership was predicted by several clinical factors, screening for which may be useful in predicting cognitive trajectories after COVID-19 hospitalization.