title: Prevalence of dementia in Japan: a systematic review.
abstract: OBJECTIVE
  The actual prevalence of dementia in Japan as well as the changes in the prevalence are not well known. Therefore, we undertook a systematic review to collect evidence regarding the prevalence of dementia in Japan.
  
  
  METHODS
  For this systematic review, we searched 2 electronic databases to identify cross-sectional or repeated cross-sectional studies with data regarding the study population, study location, diagnostic criteria, and prevalence of dementia.
  
  
  RESULTS
  Twenty-one studies were selected from 782 references. Sixteen studies surveyed individuals living at home; of these, 5 studies also included hospitalized or institutionalized patients. Most of the studies were conducted using a two-phase survey (phase I: screening, phase II: diagnosis of dementia). The clinical diagnosis of dementia was made based on the guidelines of the Diagnostic and Statistical Manual of Mental Disorders (DSM) in a majority of the studies. The prevalence of all types of dementia ranged from 2.9 to 12.5% and has been gradually increasing over the past few years.
  
  
  CONCLUSIONS
  The results of this systematic review suggest that the prevalence of dementia has recently increased. However, further well-designed studies taking into account factors that affect the prevalence of dementia are needed to clarify the actual prevalence.
authors.affiliation: Department of Psychosocial Rehabilitation, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan. hokamura @ hiroshima-u.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Shinya
authors.initials: S
authors.lastname: Ishii
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ishii
authors.forename: Akira
authors.initials: A
authors.lastname: Eboshida
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D005843:Geography; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D015995:Prevalence; D012424:Rural Population; D014505:Urban Population