Date of Award

Spring 2020

Document Type

Open Access Dissertation


Epidemiology and Biostatistics

First Advisor

Matthew Lohman


Research has examined the relationship between neighborhood environments and cognitive decline, yet few have investigated the role of neighborhood characteristics specifically on incident Alzheimer’s disease and related dementias (ADRD), on severity of Alzheimer’s disease (AD) including neuropsychiatric symptoms (NPS), and on caregiver mental health including depressive symptoms. This dissertation aimed to 1) ecologically examine the geographic distribution of ADRD and investigate ecologic associations between census-tract neighborhood characteristics and diagnosed ADRD case incidence from 2010-2014 in the South Carolina (SC) Alzheimer’s Disease Registry; 2) estimate the cross-sectional association between neighborhood characteristics and NPS among those with AD in 2010 in SC; and 3) estimate the cross-sectional association between neighborhood characteristics and mental health outcomes among AD caregivers co-habited with their care recipient in 2010 in SC.

This dissertation utilized the SC Alzheimer’s Disease Registry, which is unique and comprehensive in its documentation of ADRD cases from many different sources. Additionally, this dissertation utilized collected secondary data from the Registry in 2010. Analyses for the first aim took place on the census-tract level (n=1,089) with population ³50. Analyses for the second and third aims took place on the spatial buffer level defined as ½-mile and 1-mile, respectively. Neighborhood measures came from the Decennial Census, American Community Survey, Rural Urban Commuting Area Code, and County Health Rankings. To estimate the ecologic association for the first aim, a Poisson mixed-effects model was estimated. To estimate the cross-sectional associations for the second and third aims, negative binomial models were estimated.

Overall, we observed that those living in high poverty and low-income neighborhoods had greater incidence of ADRD, NPS, and poor caregiver mental health compared to those living in low poverty and high-income neighborhoods. Contrary to previous findings, our results suggest that those living in rural areas had lower incidence of ADRD, NPS and poor caregiver mental health compared to those living in urban areas. The potential reasons for these findings remain unclear.

Collectively, this dissertation suggests that the neighborhood environments may be an important new consideration in research exploring risk for and management of ADRD, NPS, and caregiver mental health. Future research should investigate additional neighborhood characteristics, such as green space, pollution rates, or psychosocial stress, that contribute to greater ADRD, NPS, and caregiver health.