Cognitive impairment among the elderly in a Korean rural community.

Cognitive function among the elderly aged 65 or older was studied in a rural community of Korea. The prevalence rates of cognitive impairment were significantly higher in females (64%) than in males (33%). Sex differences of prevalence of both mild impairment (25% in males vs 45% in females) and severe (8% in males vs 19% in females) reached statistically significant levels. The prevalence of severe impairment increased with age, and the age-related increase was steeper after 80 in males and after 75 in females. The prevalence of mild impairment, on the other hand, did not increase so prominently with aging. From this point of view, it could be assumed that severe cognitive impairment may be highly related to real dementia, and that the elderly with mild impairment may consist of heterogenous groups associated with cognitive dysfunction of mild degree.