Working criteria of mild cognitive impairment in community: findings from Gwangju Dementia and Mild Cognitive Impairment Study (GDEMCIS)

Introduction: The clinical determination of relative severity of impairment along the spectrum of mild cognitive impairment (MCI) may be valuable for the prediction of dementia. The purpose of the present study is to suggest the working criteria of MCI based on severity in the community sample. Methods: The MCI group was divided into three groups by severity according to cognitive and functional status. The grade I MCI group was based on the original concept of Petersen's MCI. The grade II MCI group was in the same condition as grade I MCI, except that the general cognitive function was not intact. The grade III MCI group was defined as the condition not essentially preserved instrumental to the activity of daily living, but not definite in dementia regardless of general cognitive and functional state. Results: A total of 38.5% of the subjects were classified as not cognitively impaired (NCI), 41.4% as MCI, and 10.3% as having dementia. Preliminary results showed that the grades I, II, and III MCI groups had a tendency to lie between the NCI and dementia groups. Discussion: Prospective cohort studies with clinical correlations are needed to determine whether our working criteria of MCI considering characteristics of the rural elderly, such as low education and less comprehensive activities of daily living (ADL), would be useful.