Trajectories of Cognitive Function and Their Associated Factors in Community-Dwelling Older Adults by Living Arrangement Using the Korean Longitudinal Study of Aging

Abstract

The purpose of this study was to describe the distinct cognitive trajectories for 8 years according to living arrangement among community-dwelling older adults using the Korean longitudinal study of ageing.We analyzed data from a final sample of 3,049 community-dwelling older adults aged 65 years or older who participated in at least three cognitive function measures in an 8-year period (2012-2020). Cognitive function was assessed by Korean mini mental state examination. Latent class growth model analysis was applied to determine the number and shape of trajectories of older adults according to living arrangement. Multinomial logistic regression analysis was used to determine risk factors for cognitive function trajectories.We identified five trajectory patterns in cognitive function among older adults living alone; ‘high-stable (35.6%)’, ‘high-declining (32.5%)’, ‘moderate-steep declining (6.2%)’, ‘low-stable (18.9%)’, and ‘low declining (6.8%)’. In older adults living with family, there were four trajectory patterns; ‘high-stable (46.4%)’, ‘high-declining (32.0%)’, ‘low-stable (15.9%)’, and ‘low-declining (5.7%)’. Age, instrumental activities of daily living, and depression were common factors of cognitive changes in both older adults living alone and those living with family members. However, monthly incomes was only associated with the risk of cognitive function in older adults living alone.We found that cognitive function trajectories among older adults may differ depending on the type of living arrangement. Therefore, further studies and health policies are required for avoiding cognitive impairment by living arrangement among older adults based on the results of this study.