title: Prevalence of dementia in Latin America, India, and China: a population-based cross-sectional survey.
abstract: BACKGROUND
  Studies have suggested that the prevalence of dementia is lower in developing than in developed regions. We investigated the prevalence and severity of dementia in sites in low-income and middle-income countries according to two definitions of dementia diagnosis.
  
  
  METHODS
  We undertook one-phase cross-sectional surveys of all residents aged 65 years and older (n=14 960) in 11 sites in seven low-income and middle-income countries (China, India, Cuba, Dominican Republic, Venezuela, Mexico, and Peru). Dementia diagnosis was made according to the culturally and educationally sensitive 10/66 dementia diagnostic algorithm, which had been prevalidated in 25 Latin American, Asian, and African centres; and by computerised application of the dementia criterion from the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). We also compared prevalence of DSM-IV dementia in each of the study sites with that from estimates in European studies.
  
  
  RESULTS
  The prevalence of DSM-IV dementia varied widely, from 0.3% (95% CI 0.1-0.5) in rural India to 6.3% (5.0-7.7) in Cuba. After standardisation for age and sex, DSM-IV prevalence in urban Latin American sites was four-fifths of that in Europe (standardised morbidity ratio 80 [95% CI 70-91]), but in China the prevalence was only half (56 [32-91] in rural China), and in India and rural Latin America a quarter or less of the European prevalence (18 [5-34] in rural India). 10/66 dementia prevalence was higher than that of DSM-IV dementia, and more consistent across sites, varying between 5.6% (95% CI 4.2-7.0) in rural China and 11.7% (10.3-13.1) in the Dominican Republic. The validity of the 847 of 1345 cases of 10/66 dementia not confirmed by DSM-IV was supported by high levels of associated disability (mean WHO Disability Assessment Schedule II score 33.7 [SD 28.6]).
  
  
  CONCLUSIONS
  As compared with the 10/66 dementia algorithm, the DSM-IV dementia criterion might underestimate dementia prevalence, especially in regions with low awareness of this emerging public-health problem.
authors.affiliation: Facultad de Medicina Finley-Albarran, Medical University of Havana, Havana, Cuba.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Llibre Rodriguez
authors.forename: Cleusa P
authors.initials: CP
authors.lastname: Ferri
authors.forename: Daisy
authors.initials: D
authors.lastname: Acosta
authors.forename: Mariella
authors.initials: M
authors.lastname: Guerra
authors.forename: Yueqin
authors.initials: Y
authors.lastname: Huang
authors.forename: K S
authors.initials: KS
authors.lastname: Jacob
authors.forename: E S
authors.initials: ES
authors.lastname: Krishnamoorthy
authors.forename: Aquiles
authors.initials: A
authors.lastname: Salas
authors.forename: Ana Luisa
authors.initials: AL
authors.lastname: Sosa
authors.forename: Isaac
authors.initials: I
authors.lastname: Acosta
authors.forename: Michael E
authors.initials: ME
authors.lastname: Dewey
authors.forename: Ciro
authors.initials: C
authors.lastname: Gaona
authors.forename: A T
authors.initials: AT
authors.lastname: Jotheeswaran
authors.forename: Shuran
authors.initials: S
authors.lastname: Li
authors.forename: Diana
authors.initials: D
authors.lastname: Rodriguez
authors.forename: Guillermina
authors.initials: G
authors.lastname: Rodriguez
authors.forename: P Senthil
authors.initials: PS
authors.lastname: Kumar
authors.forename: Adolfo
authors.initials: A
authors.lastname: Valhuerdi
authors.forename: Martin
authors.initials: M
authors.lastname: Prince
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000145:classification / Q000453:epidemiology*; D019049:Developed Countries / Q000706:statistics & numerical data*; D003906:Developing Countries / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007843:Latin America / Q000453:epidemiology; D008297:Male; D011159:Population Surveillance / Q000379:methods*; D015995:Prevalence; D012720:Severity of Illness Index; D017678:Sex Distribution