TY - JOUR
T1 - Declining Incident Dementia Rates Across Four Population-Based Birth Cohorts
AU - Sullivan, Kevin J.
AU - Dodge, Hiroko H.
AU - Hughes, Tiffany F.
AU - Chang, Chung Chou H.
AU - Zhu, Xinmei
AU - Liu, Anran
AU - Ganguli, Mary
AU - Melzer, David
N1 - Funding Information:
This work was supported by the National Institute on Aging at the National Institutes of Health (R01 AG023651, U01 AG06782, R01 AG07562, P30 AG053760, P30 AG008017, and T32 AG000181).
Publisher Copyright:
© 2018 The Author(s). Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved.
PY - 2019/8/16
Y1 - 2019/8/16
N2 - Background: Incidence rates of dementia appear to be declining in high-income countries according to several large epidemiological studies. We aimed to describe declining incident dementia rates across successive birth cohorts in a U.S. population-based sample and to explore the influences of sex and education on these trends. Methods: We pooled data from two community-sampled prospective cohort studies with similar study aims and contiguous sampling regions: The Monongahela Valley Independent Elders Survey (1987-2001) and the Monongahela-Youghiogheny Healthy Aging Team (2006-Ongoing). We identified four decade-long birth cohorts spanning birth years 1902-1941. In an analysis sample of 3,010 participants (61% women, mean baseline age = 75.7 years, mean follow-up = 7.1 years), we identified 257 cases of incident dementia indicated by a Clinical Dementia Rating of 1.0 or higher. We used Poisson regression to model incident dementia rates by birth cohort, age, sex, education, and interactions of Sex × Cohort and Sex × Education. We further examined whether cohort effects varied by education, testing a Cohort × Education interaction and stratifying the models by education. Results: Compared to the earliest birth cohort (1902-1911), each subsequent cohort had a significantly lower incident dementia rate (1912-1921: Incidence rate ratio [IRR] = 0.655, 95% confidence interval [95% CI] = 0.477-0.899; 1922-1931: IRR = 0.387, 95% CI = 0.265-0.564; 1932-1941: IRR = 0.233, 95% CI = 0.121-0.449). We observed no significant interactions of either sex or education with birth cohort. Conclusions: A decline in incident dementia rates was observed across successive birth cohorts independent of sex, education, and age.
AB - Background: Incidence rates of dementia appear to be declining in high-income countries according to several large epidemiological studies. We aimed to describe declining incident dementia rates across successive birth cohorts in a U.S. population-based sample and to explore the influences of sex and education on these trends. Methods: We pooled data from two community-sampled prospective cohort studies with similar study aims and contiguous sampling regions: The Monongahela Valley Independent Elders Survey (1987-2001) and the Monongahela-Youghiogheny Healthy Aging Team (2006-Ongoing). We identified four decade-long birth cohorts spanning birth years 1902-1941. In an analysis sample of 3,010 participants (61% women, mean baseline age = 75.7 years, mean follow-up = 7.1 years), we identified 257 cases of incident dementia indicated by a Clinical Dementia Rating of 1.0 or higher. We used Poisson regression to model incident dementia rates by birth cohort, age, sex, education, and interactions of Sex × Cohort and Sex × Education. We further examined whether cohort effects varied by education, testing a Cohort × Education interaction and stratifying the models by education. Results: Compared to the earliest birth cohort (1902-1911), each subsequent cohort had a significantly lower incident dementia rate (1912-1921: Incidence rate ratio [IRR] = 0.655, 95% confidence interval [95% CI] = 0.477-0.899; 1922-1931: IRR = 0.387, 95% CI = 0.265-0.564; 1932-1941: IRR = 0.233, 95% CI = 0.121-0.449). We observed no significant interactions of either sex or education with birth cohort. Conclusions: A decline in incident dementia rates was observed across successive birth cohorts independent of sex, education, and age.
KW - Cognition
KW - Cognitive aging
KW - Community-based
KW - Epidemiology
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U2 - 10.1093/gerona/gly236
DO - 10.1093/gerona/gly236
M3 - Article
C2 - 30312371
AN - SCOPUS:85068481902
VL - 74
SP - 1439
EP - 1445
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
SN - 1079-5006
IS - 9
ER -