PLoS ONE (2015-01-01)

The Prevalence of Mild Cognitive Impairment in Diverse Geographical and Ethnocultural Regions: The COSMIC Collaboration.

  • Perminder S Sachdev,
  • Darren M Lipnicki,
  • Nicole A Kochan,
  • John D Crawford,
  • Anbupalam Thalamuthu,
  • Gavin Andrews,
  • Carol Brayne,
  • Fiona E Matthews,
  • Blossom C M Stephan,
  • Richard B Lipton,
  • Mindy J Katz,
  • Karen Ritchie,
  • Isabelle Carrière,
  • Marie-Laure Ancelin,
  • Linda C W Lam,
  • Candy H Y Wong,
  • Ada W T Fung,
  • Antonio Guaita,
  • Roberta Vaccaro,
  • Annalisa Davin,
  • Mary Ganguli,
  • Hiroko Dodge,
  • Tiffany Hughes,
  • Kaarin J Anstey,
  • Nicolas Cherbuin,
  • Peter Butterworth,
  • Tze Pin Ng,
  • Qi Gao,
  • Simone Reppermund,
  • Henry Brodaty,
  • Nicole Schupf,
  • Jennifer Manly,
  • Yaakov Stern,
  • Antonio Lobo,
  • Raúl Lopez-Anton,
  • Javier Santabárbara,
  • Cohort Studies of Memory in an International Consortium (COSMIC)

DOI
https://doi.org/10.1371/journal.pone.0142388
Journal volume & issue
Vol. 10, no. 11
p. e0142388

Abstract

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BACKGROUND:Changes in criteria and differences in populations studied and methodology have produced a wide range of prevalence estimates for mild cognitive impairment (MCI). METHODS:Uniform criteria were applied to harmonized data from 11 studies from USA, Europe, Asia and Australia, and MCI prevalence estimates determined using three separate definitions of cognitive impairment. RESULTS:The published range of MCI prevalence estimates was 5.0%-36.7%. This was reduced with all cognitive impairment definitions: performance in the bottom 6.681% (3.2%-10.8%); Clinical Dementia Rating of 0.5 (1.8%-14.9%); Mini-Mental State Examination score of 24-27 (2.1%-20.7%). Prevalences using the first definition were 5.9% overall, and increased with age (P < .001) but were unaffected by sex or the main races/ethnicities investigated (Whites and Chinese). Not completing high school increased the likelihood of MCI (P ≤ .01). CONCLUSION:Applying uniform criteria to harmonized data greatly reduced the variation in MCI prevalence internationally.