# Harmonizing Cognitive Assessments in Irish, English, and American Longitudinal Studies: Supporting Cross-National Research on the Epidemiology of Dementia

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2021 · $606,885

## Abstract

PROJECT SUMMARY
 This project aims to expand the resources available for cross-national research on the epidemiology of
Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD). While cognitive impairment and
dementia impose enormous burdens on families and governments around the world, and research is ongoing
in many places, there are relatively few well-harmonized studies that allow good comparative or integrative
analysis to exploit cross-national differences in determinants and outcomes of dementia. The Health and
Retirement Study (HRS) family of international longitudinal studies of aging are closely harmonized on many
dimensions of measurement and committed to public sharing of data to encourage research. The Harmonized
Cognitive Assessment Protocol (HCAP) was developed to provide a common strong foundation to achieve
more comparable assessments of impairment and dementia within this network and better harmonization to
studies outside it.
 The HCAP has already been conducted with over 3,400 US participants in the HRS and with over 1,200
participants in the English Longitudinal Study of Ageing (ELSA). This project will add an additional 1,400
participants from the Irish Longitudinal Study of Ageing (TILDA) in the Republic of Ireland and 1,000
participants from the Northern Ireland Cohort Longitudinal Study of Ageing (NICOLA). All four studies have
genomic data available to support research. As stand-alone cohorts these studies will support estimates of the
prevalence of dementia and cognitive impairment in each nation and create the opportunity for future
longitudinal follow-up to measure incidence rates. In conjunction with the larger samples of the parent studies
they can be used to create harmonized measures of cognitive status on an even larger scale to support
epidemiologic research on the full samples.
 Northern Ireland and the Republic share many genetic and environmental factors but the North
experienced unique stress due to political violence. We will study its impact on DNA methylation and on rates
of cognitive impairment and dementia. With their close association to clinical care, the Irish studies will
undertake a valuable validation of the HCAP protocol against clinical diagnoses. The Irish studies bring
uniquely valuable measures of cardiovascular health that can be studied for its association with dementia,
including neurocardiovascular instability that is a key risk factor for falls. They also have retinal imaging that
can detect cerebral microvascular disease, and detailed nutritional assessments not generally available in
population-representative studies in the US.

## Key facts

- **NIH application ID:** 10213633
- **Project number:** 5R01AG060167-03
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** DAVID R. WEIR
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $606,885
- **Award type:** 5
- **Project period:** 2019-09-01 → 2023-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10213633

## Citation

> US National Institutes of Health, RePORTER application 10213633, Harmonizing Cognitive Assessments in Irish, English, and American Longitudinal Studies: Supporting Cross-National Research on the Epidemiology of Dementia (5R01AG060167-03). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10213633. Licensed CC0.

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