1. Evidence exclusive labels in cognitive research cause unstable prevalence estimates over time.
- Author
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Richardson, Connor Duncan, Stephan, Blossom CM, Robinson, Louise, Brayne, Carol, Matthews, Fiona E, Function, Cognitive, and Studies, Ageing
- Abstract
Background: While age specific prevalence of dementia has recently declined in some high‐income countries it is unclear whether or how the milder end of the spectrum, including Mild Cognitive Impairment might also have changed across generations. This is likely to vary according to how cognitive impairment has been defined, including exclusion criteria. Previous findings from the Cognitive Function and Ageing Studies (CFAS) show prevalence of mild impairment has either increased or remained stable depending on the criteria used, while more severe impairment has decreased over time. Whether different subtypes of MCI used in contemporary studies have different time trends are not known. Method: Data are from the English sites of the population representative Cognitive Function and Ageing Studies (CFAS). In 1991 7,635 participants were interviewed in CFAS I in Cambridgeshire, Nottingham and Newcastle with 1457 being diagnostically assessed. In the same geographical areas, the CFAS II investigators interviewed 7,796 individuals in 2011. Using consensus criteria, the population was categorised into MCI and 'other cognitive impairment no dementia' OCIND. Each cognitive group was further subtyped by the domain of cognition into amnestic (aMCI and aOCIND), non‐amnestic (naMCI and naOCIND) and multi‐domain (mMCI and mOCIND) groups, memory complaints were included as an OCIND subtype. Prevalence estimates for each were calculated using multinomial logistic regression, adjusted for age, sex and education. Results were standardized to the age‐sex specific UK and global population. Result: Between 1991 and 2011 naMCI declined substantially (10.5% versus 6.3%), mMCI increased very slightly (5.9% versus 6.3%) while aMCI, whilst relatively rare, more than doubled in prevalence (1.2% versus 2.6%). In terms of OCIND, the prevalence of naOCIND has dropped (from 17.6% to 13.9%), aOCIND has increased (3.8% to 4.9%) while mOCIND has more than doubled (from 5.7% to 11.2%). Conclusion: Between 1991 and 2011 naMCI declined substantially (10.5% versus 6.3%), mMCI increased very slightly (5.9% versus 6.3%) while aMCI, whilst relatively rare, more than doubled in prevalence (1.2% versus 2.6%). In terms of OCIND, the prevalence of naOCIND has dropped (from 17.6% to 13.9%), aOCIND has increased (3.8% to 4.9%) while mOCIND has more than doubled (from 5.7% to 11.2%). [ABSTRACT FROM AUTHOR]
- Published
- 2021
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