A Longitudinal Analysis of the Cognitive Function and Related Factors in Older Adults Using a Multilevel Growth Model

Abstract

Objectives: The purpose of this study is to examine changes in the cognitive function of the elderly over time and to identify factors affecting the cognitive decline by dividing them into multidimensional factors such as socio-demographic factors, physical and mental health factors, hearing factors, and social contact factors.Methods: This study used the Korean Longitudinal Study of Aging (KLoSA). A multilevel growth model analysis was conducted on 992 elderly people aged 60 or older who had been measured repeatedly seven times from 2006 to 2018.Results: First, the results showed that the cognitive function of the elderly decreased linearly over the years. Second, the initial status of cognitive function decreased as the age increased and as education level and economic condition decreased. The change rate of the cognitive function increased as education level increased. Third, at each time point, depression level had a negative effect on cognitive function, and subjective hearing condition had a negative effect on cognitive function. These influences decreased over time.Conclusion: The lower the education level, the higher the depression level; and the worse the subjective hearing condition, the more likely the elderly are to experience cognitive decline. Because the impact on cognitive function is large in the early stages of depression and hearing loss, it is necessary to detect them early and to make appropriate intervention to prevent cognitive decline.

Predictors of Variation in the Cognitive Function Trajectories among Older Adults Living Alone: A Growth Mixture Modeling Approach

“…As age increases, the probability of belonging to the "Low-Level Stable Type" rather than the "High-Level Declining Type" also increases. This corresponds with previous research indicating that age has a negative impact on cognitive function [22,23]. Therefore, it is imperative to implement interventions to mitigate cognitive decline related to aging, taking into account different age groups among older adults.…”

“…According to the results of this study, the average cognitive function of older individuals living alone has gradually declined over time. In contrast to studies on older individuals who have shown no cognitive changes over a 14-year period [44], it aligns with the majority of previous research results that suggest cognitive decline with increasing age [23,38,39]. The results of this study suggest that older individuals living alone require continued social attention and intervention to improve their cognitive function.…”

“…There has been an increase in research on the cognitive functions of older adults as a result of the aging of the population, resulting in a heightened awareness of societal concerns and burdens. As part of a study on cognitive function, the following factors were identified as factors affecting cognitive function: gender [17][18][19][20][21], age [22,23], education [22,[24][25][26], residential area [27][28][29][30], economic status such as income and occupation [23,26,27,31], physical health [32], and mental health, including depression [22,[33][34][35][36][37].…”

“…According to recent longitudinal studies, it has been demonstrated that cognitive function changes as individuals age. Cognitive function tends to decline with advancing age [23,38]. In contrast to the modest range of cognitive change associated with increasing age before the age of 70, the rate increased between the ages of 70 and 80 [39].…”