Cognitive function level and chronic disease incidence rate by age of older adults living in the community

Abstract

AbstractBackgroundResearch has shown that decline in cognitive function is related to the level of chronic disease in old age. Most studies, however, have either examined limited aspects of cognitive function or used assessment tools with low accuracy. A limited range of cognitive function items and low‐accuracy cognitive function assessment tools may bias the findings. Current literature also has paid little attention to the age‐gradient association between cognitive function and chronic diseases. Utilizing a new cognitive classification method, this study investigated cognitive function‐associated chronic diseases and their relationship with age. Empirical knowledge about the dynamic among cognitive function, changes in chronic diseases, and age may contribute to establishing comprehensive prevention and management programs of diseases in later years.MethodA total of 6,940 people aged between 55 to 105 years from the 2018 Korean Longitudinal Study of Aging panel data were included in this study. According to the Korean Mini‐Mental State Examination’s total score and instrumental activities of daily living assistance, cognitive status was classified into normal cognition, moderate cognitive impairment, and severe cognitive impairment. The Poisson regression analysis was used to calculate the incident rate ratios (IRR) of cognitive status by age and the incidence of chronic diseases.ResultThe incidence rate of chronic diseases was 1.07 times higher in the moderate cognitive impairment group (n = 4665) than in the normal cognitive group (n = 4665). In addition, it was 1.24 times higher in the severe cognitive impairment group (n = 420) than in the normal cognitive group (Table 1) and the incidence of chronic diseases according to cognitive function increased with age (figure 1).ConclusionApplying the new cognitive function classification, we found the incidence rate of age‐related chronic diseases increased with the cognitive status, indicating incidence of chronic diseases increases as the cognitive state decreases and the age increases, leading to complex chronic conditions. This finding points to the importance of an integrated program of cognitive decline prevention and the chronic disease management program, which are currently developed and implanted separately.