Defining rates of cognitive aging in adults with and without dementia using the CODA cohort

PROJECT ABSTRACT Objective: The purpose of this application is to identify a rate of normative cognitive aging (i.e., cognitive aging in individuals without a neurocognitive disorder), and determine how much quicker cognitive aging is among individuals living with Alzheimer disease or related dementias (AD/ADRD). Using data from the Children of the

Depression (CODA) cohort of the Health and Retirement Study (HRS), we will first identify a latent variable estimate of general cognitive performance (Aim 1). Afterwards, we will identify the pace of normative cognitive aging in standard deviations per year (SD/year), both unadjusted and adjusted for known covariables that

influence cognition (e.g., age, sex, race and ethnicity, education; Aim 2). Finally, we will use Centers for Medicare & Medicaid Services (CMS) data linked to the HRS to identify participants who receive a dementia diagnosis during follow-up, and determine how much faster cognitive aging is among individuals living with

AD/ADRD (Aim 3). In line with PAR-23-179, this proposal will also develop the career for early-stage investigator, Dr. Kunicki, and will serve as a basis for future NIH grant proposals. Significance: Cognitive ability declines with age, and tends to aging quicker later in life. Whereas neurocognitive disorders such AD/ADRD are known to increase the rate of cognitive aging, there is no well-

established reference of normative cognitive aging. Lacking this reference pace makes it difficult for researchers to evaluate the results of their studies (i.e., determining if a cohort is declining at a normal or quicker than usual pace). Moreover, we will estimate how much quicker cognitive aging is among individuals

living with AD/ADRD. Approach: We will use data from the CODA cohort of the HRS, which is comprised of over 2,000 participants aged 68-74 at baseline with 22-years of follow-up data available. Using the HRS cognitive measures, we will identify a latent variable of cognitive aging, and use the latent variable to identify the pace of normative

cognitive aging in SD/year. Then, using CMS data, we will identify participants who received a dementia diagnosis during follow-up and determine how much faster cognitive aging is among individuals living with AD/ADRD. Sensitivity analyses will also examine the pace of normative cognitive aging by different cognitive

domains. Innovation: This study is innovative because it addresses a major gap in the literature in cognitive aging by identifying a pace of normative cognitive aging and among individuals living with AD/DARD. These paces will be useful for researchers to use as reference points to interpret results of clinical trials to slow cognitive aging.

Despite a lack of normative cognitive aging rates being a well-known issue in the field of aging, this study will be the first to identify a nationally representative rate of cognitive aging among older adults.