PROJECT SUMMARY
Although the prevalence of Alzheimer’s disease and related dementias (ADRD) has been decreasing, the
COVID-19 pandemic may have halted or reversed that trend. This project will quantify the effects of the
pandemic and of attendant public health and social measures on the cognitive status, mortality, and well-being
of persons living with ADRD and of the older population in general. Persons living with dementia were
especially vulnerable to COVID-19 because many were living in nursing homes, and even those residing in the
community were disproportionately vulnerable because of caregivers coming to their homes. Further, those
initially not living with dementia may have experienced accelerated cognitive decline because of COVID-19
infections, as well as due to disruption of daily routines, social isolation and stress. Subpopulations by race,
ethnicity and socioeconomic status were impacted unequally.
This project has three specific aims. The first is to use a new and updated model of cognition to estimate
trends in ADRD prevalence, incidence, and mortality prior to the pandemic. We will use data from the Health
and Retirement Study (HRS), a large, nationally representative, longitudinal survey of the U.S. population over
age 50. The HRS has a wide range of information on cognitive abilities, mortality, dementia risks, and physical
and mental health, but only a subsample of the HRS from the Aging, Demographic, and Memory Study
(ADAMS) has a clinical assessment of dementia. In prior research, we used ADAMS to develop a model of the
probability of dementia to estimate the cognitive status of the entire HRS sample. In this work, we will expand
this model to estimate dementia incidence and mortality as well, and incorporate recently released data from
the Harmonized Cognitive Assessment Protocol, further increasing precision so as to permit the study of
changes in ADRD resulting from the pandemic in subpopulations, such as race and ethnicity, marital status,
and socioeconomic status.
Second, we will document changes associated with the pandemic in mortality, well-being, use of formal
and informal care, and other outcomes. We will incorporate variation in state policies to assess their effect on
individual outcomes. We will compare these effects among those who were living with dementia prior to the
pandemic to those whose cognitive function was normal. We will use innovative models and data from various
HRS supplements focusing on COVID-19 to estimate these effects with precision.
Third, we will estimate the incidence of dementia and dementia mortality after the pandemic through 2026
and find the extent to which COVID-19 altered pre-pandemic trends. We will assess whether ADRD incidence
differed by individual characteristics, such as geographic location, race, socioeconomic status, and living
arrangements. The developed cognition measures will be made publicly available to enhance future research.