Mapping the Mortality-To-Incidence Ratios of Alzheimer’s Disease and Related Dementias (ADRDs): Evidence from the South Carolina Alzheimer’s Disease Registry

Author(s)

Eric Mishio Bawa
Daniel A. Amoatika
Margaret C. Miller MS, Ph.D., University of South CarolinaFollow
Bankole A. Olatosi Ph.D., University of South CarolinaFollow
Lorie Donelle PhD, RN, FCAN, University of South CarolinaFollow
Sue E. Levkoff ScD, MSW, SM, University of South CarolinaFollow
James W. Hardin Ph.D., University of South CarolinaFollow
Xiaoming Li Ph.D., University of South CarolinaFollow
Leonardo Bonilha
Daniela B. Friedman Ph.D., University of South CarolinaFollow
Swann Arp Adams Ph.D., MS, FACE, University of South CarolinaFollow

Document Type

Article

Abstract

Introduction Mortality-to-incidence ratios (MIRs) are useful in assessing disease burdens and illustrating disparities. Unlike cancer, MIRs have not been applied to ADRDs. Therefore, we estimated and mapped the MIRs for ADRDs to show disparities in South Carolina. Methods Using data from the South Carolina Alzheimer’s Disease Registry (2017−2021), ADRD MIRs were calculated by demographic and geospatial characteristics. To account for the influence of the COVID-19 pandemic, data from 2015 to 2019 were also examined. MIRs were calculated as age-adjusted mortality rates divided by age-adjusted incidence rates. Results Overall, Black people and rural individuals consistently experienced higher MIRs, with the COVID-19 pandemic increasing this disparity gap. MIRs greater than 1.00 were only observed among Black people. The MIR for 31 out of 46 counties exceeded the state average. Discussion Estimating and mapping ADRDs has aided in identifying specific areas with the greatest burden of ADRD in South Carolina for targeting interventions.

Digital Object Identifier (DOI)

https://doi.org/10.1371/journal.pone.0339785

Publication Info

Published in PLoS One, Issue 12 December, 2025.

APA Citation

Mishio Bawa, E., Amoatika, D. A., Miller, M. C., Olatosi, B. A., Donelle, L., Levkoff, S. E., Hardin, J. W., Li, X., Bonilha, L., Friedman, D. B., & Adams, S. A. (2025). Mapping the mortality-to-incidence ratios of Alzheimer’s Disease and Related Dementias (ADRDs): Evidence from the South Carolina Alzheimer’s disease registry. PLoS One, 20(12), e0339785.https://doi.org/10.1371/journal.pone.0339785

Rights

© 2025 Mishio Bawa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.