title: Prevalence and cognitive performances of clinical dementia rating 0.5 and mild cognitive impairment in Japan. The Tajiri project.
abstract: The borderline zone condition between normal aging and dementia is a major issue of concern. Although the term mild cognitive impairment (MCI) is popular, its prevalence and neuropsychological features have not been fully investigated. We investigated the prevalence and neuropsychological features for Clinical Dementia Rating (CDR) 0.5 and MCI. For normal aging, the effects of age and educational level on cognitive performance were examined. We examined 1501 older residents (46.8%) in Tajiri 65 years of age and older. They performed the Cognitive Abilities Screening Instrument (CASI). Depressive scores and subjective memory complaints were also evaluated. There was no age effect but an educational effect on cognitive performance in healthy adults. We found the overall prevalence of CDR 0.5 to be 30.2%, whereas that of MCI was only 4.9%. All CASI domains were deteriorated except for long-term memory and visual construction in the CDR 0.5 participants compared with healthy adults, suggesting that CDR 0.5 is similar to very mild Alzheimer disease. Memory complaints' data suggested that it would be better to exclude memory complaints from the MCI criteria. We considered that the concept of CDR 0.5 would be more applicable to community residents rather than that of the MCI.
authors.affiliation: Division of Neuropsychology, Department of Disability Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. meg@mail.cc.tohoku.ac.jp
authors.forename: Kenichi
authors.initials: K
authors.lastname: Meguro
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishii
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Junichi
authors.initials: J
authors.lastname: Ishizaki
authors.forename: Mari
authors.initials: M
authors.lastname: Sato
authors.forename: Ryusaku
authors.initials: R
authors.lastname: Hashimoto
authors.forename: Mitsue
authors.initials: M
authors.lastname: Meguro
authors.forename: Eunjoo
authors.initials: E
authors.lastname: Lee
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Kasuya
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Sekita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D003072:Cognition Disorders / Q000145:classification* / Q000453:epidemiology*; D003704:Dementia / Q000145:classification* / Q000453:epidemiology*; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012720:Severity of Illness Index