Incidence of dementia after age 90 in a multiracial cohort

Paola Gilsanz; Maria M Corrada; Claudia H Kawas; Elizabeth Rose Mayeda; M Maria Glymour; Charles P Quesenberry Jr; Catherine Lee; Rachel A Whitmer

doi:10.1016/j.jalz.2018.12.006

Incidence of dementia after age 90 in a multiracial cohort

Alzheimers Dement. 2019 Apr;15(4):497-505. doi: 10.1016/j.jalz.2018.12.006. Epub 2019 Feb 20.

Authors

Paola Gilsanz¹, Maria M Corrada², Claudia H Kawas³, Elizabeth Rose Mayeda⁴, M Maria Glymour⁵, Charles P Quesenberry Jr¹, Catherine Lee¹, Rachel A Whitmer⁶

Affiliations

¹ Kaiser Permanente Division of Research, Oakland, CA, USA.
² Department of Neurology, University of California, Irvine, Irvine, CA, USA; Department of Epidemiology, University of California, Irvine, Irvine, CA, USA.
³ Department of Neurology, University of California, Irvine, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, USA.
⁴ Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, USA.
⁵ Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
⁶ Kaiser Permanente Division of Research, Oakland, CA, USA; Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA; Department of Public Health Sciences, University of California, Davis, Davis, CA, USA. Electronic address: rawhitmer@ucdavis.edu.

Abstract

Introduction: Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.

Methods: Incident dementia diagnoses from 1/1/2010 to 9/30/2015 were abstracted from medical records for 2350 members of an integrated health care system in California (n = 1702 whites, n = 375 blacks, n = 105 Latinos, n = 168 Asians) aged ≥90 in 2010. We estimated race/ethnicity-specific age-adjusted dementia incidence rates and implemented Cox proportional hazards models and Fine and Gray competing risk of death models adjusted for demographics and comorbidities in midlife and late-life.

Results: Dementia incidence rates (n = 771 cases) were lowest among Asians (89.9/1000 person-years), followed by whites (96.9/1000 person-years), Latinos (105.8/1000 person-years), and blacks (121.5/1000 person-years). Cox regression and competing risk models estimated 28% and 36% higher dementia risk for blacks versus whites adjusting for demographics and comorbidities.

Discussion: Patterns of racial/ethnic disparities in dementia seen in younger older adults continue after the age of 90 years, though smaller in magnitude.

Keywords: Dementia; Disparities; Epidemiology; Ethnicity; Oldest-old; Race.

Publication types

Research Support, N.I.H., Extramural

MeSH terms

Aged, 80 and over
Cohort Studies
Dementia / epidemiology*
Dementia / ethnology*
Ethnicity / statistics & numerical data*
Female
Humans
Incidence
Male

Abstract

Publication types

MeSH terms

Grants and funding