Cumulative socioeconomic exposures, cash transfer interventions, and later-life cognitive decline and dementia risk in a low-income region of South Africa. This project aims to determine how cumulative, randomized, and quasi-randomized socioeconomic exposures in mid-to-later- life affect memory decline and dementia risk in later-life, by linking three unique population data sources in South Africa that cover a 22-year period from 2000 to 2021. These contributions will provide robust evidence on dementia etiology and will serve as sentinel findings for prevention strategies not only in sub-Saharan Africa, where there is currently little data outside of this study, but also for guiding interventions in dementia prevention programs. Dr. Kobayashi is co-leading this project with Dr. Molly Rosenberg at Indiana University.
Funding: National Institute on Aging, R01AG069128 (PIs: Rosenberg and Kobayashi)
Socioeconomic and cardiovascular sources of cross-national variation in cognitive health among older adults.
This project aims to estimate the contributions of key socioeconomic and cardiovascular dementia risk factors to later-life cognitive function between individuals and between countries in the US Health and Retirement Study (HRS) and its International Partner Studies (IPS) in South Africa, Mexico, India, and England. We aim to: 1) statistically harmonize measures from the Harmonized Cognitive Assessment Protocol (HCAP) across HRS/IPS countries using modern psychometrics to enable us to identify and address any differential item functioning of HCAP measures across countries in order to facilitate valid cross-national comparisons; 2) investigate and quantify the contributions of life course socioeconomic factors to variation in later-life cognitive function between individuals and between countries; and, 3) investigate and quantify the contributions of cardiovascular factors to variation in later-life cognitive function between individuals and between countries. Our results will set the stage to identify intervention targets for high-risk individuals as well as whole populations, with the ultimate goal of preventing and/or delaying the onset of dementia from a global perspective. Dr. Kobayashi is co-leading this project with Dr. Alden Gross at Johns Hopkins Bloomberg School of Public Health.
Funding: National Institute on Aging, R01AG070953 (PIs: Kobayashi and Gross)
Immunosenescence, socioeconomic disadvantage and dementia in the US aging population. This project seeks to improve our understanding of the pathophysiology of cognitive decline and ADRD by examining the role of peripheral immunosenescence in these processes. Using the Health and Retirement Study (HRS), we will examine associations between peripheral immunosenescence and cognitive function, decline, and incident ADRD, with specific attention to social inequalities in these processes. At its conclusion, this study will yield critical insights to our understanding of the pathophysiology of cognitive decline and ADRD, creating new opportunities for early detection and targeting at the population level. Dr. Kobayashi is a Co-Investigator on this project, which is led by Dr. Grace Noppert at the University of Michigan and Dr. Allison Aiello at UNC Chapel Hill. Funding: National Institute on Aging, R01AG075719 (PIs: Noppert and Aiello)
Identifying and Addressing Social Determinants of Health to Reduce the National Burden of and Inequities in Dementia. Our overall objective is to use large multilevel, longitudinal datasets and quasi-experimental approaches to construct the first comparative assessment evidence base on the social drivers of ADRD burden and inequities. We will accomplish our overall objective using data in adults age 50+ from: the nationally-representative Mortality Disparities in American Communities Study, linked to national mortality databases; the nationally-representative Health and Retirement Study, linked to Medicare claims data; and the NIH’s All of Us Program, a multiethnic study linked to electronic health records (EHR) data on diagnoses/treatments of health conditions. We will identify the most promising SDoH on which to intervene to yield improvements in ADRD burden and inequities. We will further establish the pathways to differential vulnerabilities by subpopulation. By translating estimates into population health metrics, we anticipate our project will have high translational impact through guiding policymakers’ evidence-based decisions about policies to more effectively reduce the burden of and inequities in ADRD among Americans. Dr. Kobayashi is a Co-Investigator on this project, which is led by Dr. Daniel Kim at Northeastern University. Funding: National Institute on Aging, RF1AG075916 (PI: Kim)
The COVID-19 Coping Study: A longitudinal mixed-methods study of older adults’ mental health and well-being during the COVID-19 pandemic in the United States. We are conducting an ongoing study of over 4,000 men and women aged 55 and over in the United States to evaluate month-by-month changes in mental health and well-being, particularly in relation to social and economic changes as a result of the COVID-19 pandemic. We are tracking changes in employment, living circumstances, self-isolation and other necessary COVID-19 control measures, access to parks and green space, and coping strategies employed by older adults. Ultimately, we aim for results to inform equitable public health interventions and clinical practices to harness positive coping strategies, foster social support, and encourage meaningful daily activities among older populations during times of stress and trauma.
Learn more about the COVID-19 Coping Study on our study website!
Previous studies
Education and cancer-related cognitive decline during aging. Education predicts better cognitive function in older adults generally and substantially reduces dementia risk, but is largely unexplored in the US general population of middle-aged and older cancer survivors. With innovative use of data that were collected prior to cancer diagnosis in order to rule out reverse causation and a follow- up period of up to 16 years after cancer diagnosis, this research will illuminate the risk modifying roles of education and other cognitive reserve markers in cancer-related cognitive decline at the general population level. We are using data from the nationally representative US Health and Retirement Study and linked Medicare data from 1998-2016. We use segmented linear mixed models to estimate memory change prior to and after a new cancer diagnosis and treatment across levels of cognitive reserve markers, with age-matched cancer-free adults as a comparison group. This research is a first step towards achieving our long-term goal of understanding and improving cognitive aging outcomes in the growing population of older cancer survivors.
Funding: National Cancer Institute, R03CA241841 (PI: Kobayashi)
SOCIAL EPIDEMIOLOGY OF GLOBAL AGING (SEGA) RESEARCH GROUP 