Prevalence and Clinical Predictors of Cognitive Impairment in Individuals Aged 80 Years and Older in Rural China

Abstract

Aims: The aim of this study was to estimate the prevalence of cognitive impairment (CI) in individuals aged 80 years and over in rural China and to analyze the associated risk factors. Methods: We conducted a two-phase door-to-door survey of a population in rural Ji County (China). The reference population consisted of individuals aged 80 years or older. A total of 723 individuals were interviewed in their homes, and demographic variables and comorbidities were recorded. Diagnoses were divided into the following 3 categories: normal cognitive function, cognitive impairment no dementia (CIND), and dementia. The odds ratio for each risk factor was calculated by logistic regression analysis. Results: The prevalence of CI among individuals aged 80 years and older was 73.2% (47.4% CIND and 25.7% dementia). The risk of CI decreased with a higher level of education and a higher level of social involvement. The risk of CI was higher in females than in males and among people with a history of stroke (p < 0.01). Conclusions: The observed raw prevalence of CI was 73.2%. Female gender and a history of a previous stroke increased the risk of CI, while a higher educational level and engagement in social activities reduced the risk of CI.