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

• Main Authors: 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)
• Format: Article
• Language: English
• Published: Public Library of Science (PLoS) 2015-01-01
• Series: PLoS ONE
• Online Access: http://europepmc.org/articles/PMC4634954?pdf=render
• ISSN: 1932-6203

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.