Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study
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Date
2020-12-18
Open Access Location
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central Ltd
Rights
(c) 2020 The Author/s
CC BY 4.0
CC BY 4.0
Abstract
Background
Subjective cognitive decline (SCD) is recognized as a risk stage for Alzheimer’s disease (AD) and other dementias, but its prevalence is not well known. We aimed to use uniform criteria to better estimate SCD prevalence across international cohorts.
Methods
We combined individual participant data for 16 cohorts from 15 countries (members of the COSMIC consortium) and used qualitative and quantitative (Item Response Theory/IRT) harmonization techniques to estimate SCD prevalence.
Results
The sample comprised 39,387 cognitively unimpaired individuals above age 60. The prevalence of SCD across studies was around one quarter with both qualitative harmonization/QH (23.8%, 95%CI = 23.3–24.4%) and IRT (25.6%, 95%CI = 25.1–26.1%); however, prevalence estimates varied largely between studies (QH 6.1%, 95%CI = 5.1–7.0%, to 52.7%, 95%CI = 47.4–58.0%; IRT: 7.8%, 95%CI = 6.8–8.9%, to 52.7%, 95%CI = 47.4–58.0%). Across studies, SCD prevalence was higher in men than women, in lower levels of education, in Asian and Black African people compared to White people, in lower- and middle-income countries compared to high-income countries, and in studies conducted in later decades.
Conclusions
SCD is frequent in old age. Having a quarter of older individuals with SCD warrants further investigation of its significance, as a risk stage for AD and other dementias, and of ways to help individuals with SCD who seek medical advice. Moreover, a standardized instrument to measure SCD is needed to overcome the measurement variability currently dominant in the field.
Description
Keywords
Cohort study, Data harmonization, Epidemiology, Individual participant data, Prevalence, Subjective cognitive decline, Aging, Cognitive Dysfunction, Cohort Studies, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Prevalence
Citation
Röhr S, Pabst A, Riedel-Heller SG, Jessen F, Turana Y, Handajani YS, Brayne C, Matthews FE, Stephan BCM, Lipton RB, Katz MJ, Wang C, Guerchet M, Preux P-M, Mbelesso P, Ritchie K, Ancelin M-L, Carrière I, Guaita A, Davin A, Vaccaro R, Kim KW, Han JW, Suh SW, Shahar S, Din NC, Vanoh D, van Boxtel M, Köhler S, Ganguli M, Jacobsen EP, Snitz BE, Anstey KJ, Cherbuin N, Kumagai S, Chen S, Narazaki K, Ng TP, Gao Q, Gwee X, Brodaty H, Kochan NA, Trollor J, Lobo A, López-Antón R, Santabárbara J, Crawford JD, Lipnicki DM, Sachdev PS, for Cohort Studies of Memory in an International Consortium (COSMIC) . (2020). Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study.. Alzheimers Res Ther. 12. 1. (pp. 167-).