In this report, the authors evaluate the predictive power of 181 potential risk factors for dementia and cognitive impairment using validated probabilistic measures from the Health and Retirement Study, a large, nationally representative, longitudinal survey of the U.S. population over age 50. The authors estimate how these factors predict cognitive impairment and dementia for individuals two, four, and twenty years after age 60.

Identifying Early Predictors of Cognitive Impairment and Dementia in a Large Nationally Representative U.S. Sample

Peter Hudomiet, Michael D. Hurd, Susann Rohwedder

ResearchPublished Dec 3, 2024

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The number of older adults in the United States and worldwide is growing, and because age is the most important predictor of dementia, the number of persons living with this condition is also expected to grow. Detecting elevated risk for dementia years before its onset would help older adults prepare for the risk of developing this condition and guide health-care providers, policymakers, and the government to more efficiently target resources to delay the onset or mitigate the effects of this condition. To support these efforts, the authors of this report aim to identify the predictors of dementia and cognitive impairment for individuals in the United States up to 20 years in advance of the onset of this condition, using the cognition and dementia measures from the Health and Retirement Study (HRS), a large, nationally representative, longitudinal survey of the U.S. population over age 50.

In this report, the authors evaluate the predictive power of 181 potential risk factors, including demographics, socioeconomic status (SES), labor-market measures, lifestyle and health behaviors (such as exercising and smoking), subjectively reported and objectively measured health, genes, parental health, cognitive abilities, and psychosocial factors (such as personality traits, social activities, and loneliness). The authors estimate how these factors predict cognitive impairment and dementia for individuals two, four, and twenty years after age 60. 

Key Findings

  • The authors predicted quantitatively meaningful and statistically significant variation in dementia prevalence among persons approximately age 80 according to individuals' observed characteristics when they were about age 60.
  • An individual's baseline cognitive abilities, health, and functional limitations are the strongest predictors of dementia, whereas parental health, family size, marital history, and demographics are the weakest ones.
  • Having poor physical health, a stroke, lower cognitive abilities, functional limitations, and particular genes strongly predict future incidence and prevalence of cognitive impairment and dementia.
  • Individuals born in the Southern United States face higher chances of developing cognitive impairment and dementia, even when controlling for an expanded set of factors.
  • Other factors associated with a higher chance of developing cognitive impairment or dementia are not having a private health insurance plan at age 60, never having worked or having worked only a few years, having diabetes or a body mass index of 35 or more at age 60, never drinking alcohol or drinking excessively, never exercising, scoring low on various physical tests, being less conscientious, and having low engagement in hobbies and novel information activities.
  • Black and Hispanic individuals face higher chances of cognitive impairment and dementia, but these differentials shrink or disappear when accounting for observable differences, such as SES.

Recommendations

  • Older individuals striving to maintain high cognitive function for a longer time might benefit from early lifestyle modifications, such as performing physical exercise, working additional years, engaging in hobbies and novel information activities after retirement, and maintaining good physical health.
  • Policymakers and health-care providers should consider ways of promoting healthy behaviors in the adult population and strengthening individuals' access to quality health care.
  • Increased precision in the prediction of dementia prevalence in the population would help to plan for the evolution of the very high monetary and caregiving costs associated with dementia.
  • Identifying individuals at elevated risk for dementia would permit the channeling of resources to them that could encourage them to engage in planning to pursue a lifestyle that promotes brain health.

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Hudomiet, Peter, Michael D. Hurd, and Susann Rohwedder, Identifying Early Predictors of Cognitive Impairment and Dementia in a Large Nationally Representative U.S. Sample, RAND Corporation, RR-A3207-1, 2024. As of April 30, 2025: https://www.rand.org/pubs/research_reports/RRA3207-1.html

Chicago Manual of Style

Hudomiet, Peter, Michael D. Hurd, and Susann Rohwedder, Identifying Early Predictors of Cognitive Impairment and Dementia in a Large Nationally Representative U.S. Sample. Santa Monica, CA: RAND Corporation, 2024. https://www.rand.org/pubs/research_reports/RRA3207-1.html.
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This research was sponsored by Genentech and conducted in the Social and Behavioral Policy Program within RAND Social and Economic Well-Being.

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