Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study

Susanne Röhr (1, 2) , Alexander Pabst (1) , Steffi Riedel-Heller (1) , Frank Jessen (3, 4) , Yuda Turana (5) , Yvonne Handajani (5) , Carol Brayne (6) , Fiona Matthews (7, 8) , Blossom Stephan (9) , Richard Lipton (10) , Mindy Katz (10) , Cuiling Wang , Maëlenn Guerchet (11) , Pierre-Marie Preux (11, 12, 13) , Pascal Mbelesso (11) , Karen Ritchie (14) , Marie-Laure Ancelin (14) , Isabelle Carrière (14) , Antonio Guaita (15) , Annalisa Davin (16) , Roberta Vaccaro (15) , Ki Woong Kim (16) , Ji Won Han (16) , Seung Wan Suh (16) , Suzana Shahar (17) , Normah Din (18) , Divya Vanoh (19) , Martin van Boxtel (20) , Sebastian Köhler (20) , Mary Ganguli (20) , Erin Jacobsen (20) , Beth Snitz (20) , Kaarin Anstey (21) , Nicolas Cherbuin (21) , Shuzo Kumagai (21) , Sanmei Chen , Kenji Narazaki , Tze Pin Ng , Qi Gao , Xinyi Gwee , Henry Brodaty , Nicole Kochan , Julian Trollor , Antonio Lobo , Raúl López-Antón , Javier Santabárbara , John Crawford , Darren Lipnicki , Perminder Sachdev

1 ISAP - Occupational Health and Public Health
2 Trinity College Dublin
3 Faculty of Medicine [Cologne]
4 DZNE, Bonn, Germany
5 Faculty of Medicine [Jakarta, Indonesia]
6 Institute of Public Health - Department of Public Health and Primary Care [Cambridge, UK]
7 MRC Biostatistics Unit [Cambridge, UK]
8 Institute of Health & Society [Newcastle upon Tyne, UK]
9 Institute of Health & Society
10 Saul B. Korey Department of Neurology
11 NET - Neuroépidémiologie Tropicale
12 SIME - Service de l'Information Médicale et de l'Évaluation [CHU Limoges]
13 Laboratoire de Biostatistique et d'Informatique Médicale
14 Edin. - University of Edinburgh
15 SNU - Seoul National University [Seoul]
16 Seoul National University Hospital
17 UKM - Universiti Kebangsaan Malaysia
18 USM - Universiti Sains Malaysia
19 MUMC - Maastricht University Medical Centre
20 University of Pittsburgh School of Medicine
21 University of Fukuoka

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.

Mots clés: Cohort study; Data harmonization; Epidemiology; Individual participant data; Prevalence; Subjective cognitive decline

Domaines: Santé publique et épidémiologie

Susanne Röhr, Alexander Pabst, Steffi Riedel-Heller, Frank Jessen, Yuda Turana, et al.. Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study. Alzheimer's Research and Therapy, 2020, 12 (167), ⟨10.1186/s13195-020-00734-y⟩. ⟨hal-03105760⟩