A 6-Year Follow-up of Cognitive Function in a Rural Elderly Population

Park, Jonghan; Lee, Yang Hyun; Kim, Heecheol

Abstract

OBJECTIVES: This study was conducted to delineate the long-term natural change of cognitive functions in aged community residents, using the Korean version of the mini-mental state examination (MMSEK)
METHODS
The first MMSEK was administered to as the screening test for identification of dementia between January and December, 1990 in a total of 702 persons. They were residents of a Myun area, Pohang, Kyungpook Province and 65 or more as of December 31. 1990. The MMSEK was repeated from November, 1995 to June, 1996, using the Cognitive Impairment Diagnosing Instrument and was successful in 440.
RESULTS
The 6-year mean(+/-SD) decline of the total MMSEK score was 1.52+/-3.45 and 6.42%. Of the subtests, memory registration showed no significant decline while comprehension/judgement improved significantly. The decline was most prominent in attention/calculation and memory recall, and then language, orientation in time and orientation in place in order. Change of the total score was not related to sex, education and the first total score. Decline of language function was more severe in the educated than in the noneducated-illiterate. Performances of all subtests declined significantly with aging and improvement of the comprehension/judgement was less prominent in the group aged 75 or more. Relations of the change with the first total score were inconsistent among the subtests. The stepwise multiple regression analysis revealed that age, the first total score and education were the variables significantly affecting the decline of MMSEK score. However, they could account for only 16.4% of the variance of decline of the total MMSEK score.
CONCLUSIONS
Decline of the cognitive function was small during the 6-year period, and the change pattern was not homogenous among the subtests. Age, the first total MMSEK score and education were idenrified as significant, but not so important, factors accounting for the variance of the cognitive decline.