title: Occurrence of cognitive impairment and dementia after the age of 60: a population-based study from Northern Italy.
abstract: OBJECTIVE
  To evaluate the age, gender and education distribution of both cognitive impairment and dementia in the whole old age range of the elderly (from 61 years of age and over).
  
  
  METHODS
  The study population consisted of all subjects born in 1930 or before, living in the municipality of Faenza and Granarolo, Italy (n = 7,930). A two-phase study design was implemented, by using the Mini-Mental State Examination and Global Deterioration Scale as screening instruments. The DSM-III-R diagnostic criteria were used for the clinical diagnosis of dementia. A subject was classified as affected by cognitive impairment, no dementia (CIND) if he/she scored 2 or more standard deviations lower than the corrected mean MMSE score.
  
  
  RESULTS
  The prevalences of dementia and CIND were 6.5 per 100 (95% CI 5.9-7.0) and 5.1 per 100 (95% CI 4.6-5.6), respectively. The prevalence of CIND was higher than that of dementia in the youngest old groups (61-74 years), both in men and women, whereas the opposite pattern was present among the older old (75+). In the older age groups, dementia prevalence increased exponentially with age, while CIND prevalence was more stable. There was not a substantial gender difference in CIND prevalence in all ages. Only in the subpopulation of higher educated subjects, women had a higher prevalence of both dementia and CIND than men. Lower educated subjects had a higher prevalence of both dementia and CIND. When compared to higher educated persons, subjects without any schooling had odds ratios of 10.9 (CI 7.0-16.7) and 16.7 (CI 11.2-25.0) for dementia and CIND, respectively.
  
  
  CONCLUSIONS
  Cognitive impairment is very common in the younger old ages (under 70 years of age), whereas dementia becomes predominant after 75 years of age. Both conditions are strongly related to the educational level.
authors.affiliation: Institute of Psychiatry, University of Bologna, Bologna, Italy. Diana.de.Ronchi@neurotec.ki.se
authors.forename: Diana
authors.initials: D
authors.lastname: De Ronchi
authors.forename: Domenico
authors.initials: D
authors.lastname: Berardi
authors.forename: Marco
authors.initials: M
authors.lastname: Menchetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ferrari
authors.forename: Alessandro
authors.initials: A
authors.lastname: Serretti
authors.forename: Edoardo
authors.initials: E
authors.lastname: Dalmonte
authors.forename: Laura
authors.initials: L
authors.lastname: Fratiglioni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006306:Health Surveys; D006801:Humans; D007558:Italy; D008297:Male; D008609:Mental Status Schedule / Q000706:statistics & numerical data; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D016017:Odds Ratio; D011159:Population Surveillance; D011379:Prognosis; D011594:Psychometrics / Q000706:statistics & numerical data