27-year time trends in dementia incidence in Europe and the US: the Alzheimer Cohorts Consortium

Frank J. Wolters, Lori B Chibnik, Reem Waziry, Roy Anderson, Claudine Berr, Alexa Beiser, Joshua C Bis, Deborah Blacker, Daniel Bos, Carol Brayne, Jean-Francois Dartigues, Sirwan KL Darweesh, Kendra L Davis-Plourde, Frank de Wolf, Stephanie Debette, Carole Dufouil, Myriam Fornage, Jaap Goudsmit, Leslie Grasset, Vilmundur GudnasonMatthew P. Pase

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Abstract

Objective: To determine changes in the incidence of dementia between 1988 and 2015. Methods: This analysis was performed in aggregated data from individuals >65 years in seven population-based cohort studies in the United States and Europe from the Alzheimer Cohort Consortium. First, we calculated age- and sex-specific incidence rates for all-cause dementia, and then defined non-overlapping 5-year epochs within each study to determine trends in incidence. Estimates of change per 10-year interval were pooled and results are presented combined and stratified by sex. Results: Of 49,202 individuals, 4,253 (8.6%) developed dementia. The incidence rate of dementia increased with age, similarly for women and men, ranging from about 4 per 1,000 person years in individuals aged 65-69 years, to 65 per 1,000 person years for those aged 85-89 years. The incidence rate of dementia declined by 13% per calendar decade (95% CI: 7%-19%), consistently across studies, and somewhat more pronouncedly in men than in women (24% [95% CI 14%-32%] versus 8% [0%-15%]). Conclusion: The incidence rate of dementia in Europe and North America has declined by 13% per decade over the past 25 years, consistently across studies. Incidence is similar for men and women, although declines were somewhat more profound in men. These observations call for sustained efforts to finding the causes for this decline, as well as determining their validity in geographically and ethnically diverse populations.
Original languageEnglish
JournalNeurology
DOIs
Publication statusAccepted/In press - 1 Jul 2020
Externally publishedYes

Cite this

Wolters, F. J., Chibnik, L. B., Waziry, R., Anderson, R., Berr, C., Beiser, A., Bis, J. C., Blacker, D., Bos, D., Brayne, C., Dartigues, J-F., Darweesh, S. KL., Davis-Plourde, K. L., de Wolf, F., Debette, S., Dufouil, C., Fornage, M., Goudsmit, J., Grasset, L., ... Pase, M. P. (Accepted/In press). 27-year time trends in dementia incidence in Europe and the US: the Alzheimer Cohorts Consortium. Neurology. https://doi.org/10.1212/WNL.0000000000010022