# The effects of study design characteristics on dementia assessment: Recommendations for future epidemiologic studies

> **NIH NIH F31** · JOHNS HOPKINS UNIVERSITY · 2022 · $31,376

## Abstract

PROJECT SUMMARY
Significance: Alzheimer’s disease and related dementias (ADRD) are a major public health challenge.
Epidemiologic research on ADRD relies on the diagnosis of dementia via cognitive testing and survey
questions on functional limitations in daily activities (i.e difficulty bathing). However, there is wide variability in
the implementation of assessments. Across 237 scientific publications on ADRD prevalence and incidence,
researchers used 230 different measurement methods. Methods varied widely in the specific tests, questions,
and algorithmic approaches used. This heterogeneity poses challenges, and is likely responsible for observed
inconsistencies in the estimation of both prevalence and the effects of modifiable risk factors such as diabetes,
a risk that will grow in importance with anticipated increases in exposure prevalence. The overarching goal of
this research is to develop guidelines to improve dementia measurement in future epidemiologic studies.
Specific Aims: We aim to characterize the effect of study design characteristics on the association between
ADRD and individual survey questions on cognition and functional impairment. Specifically, in Aim 1, we will
assess how geographic setting affects measurement in cross-national dementia research. In Aim 2, we will
assess differences between dementia measurement in cross-sectional studies focused on the ascertainment of
prevalent dementia and longitudinal studies focused on the ascertainment of incident dementia. Both Aims will:
(1) characterize variations in the associations between specific questions administered on surveys and either
cognitive functioning or dementia, and (2) quantify the impact of improvements in measurement on the
association between diabetes (an established risk factor for ADRD) and cognitive functioning or dementia.
Approach: For Aim 1 we will use data from the Harmonized Cognitive Assessment Protocol (HCAP) surveys
in the United States, Mexico, England, South Africa, and India. We will compare the associations between
each survey question with cognitive functioning, using both confirmatory factor analysis and logistic regression.
We will also use logistic regression to evaluate the association between diabetes and traditional vs. improved
short measures of cognitive functioning. Aim 2 will leverage rich longitudinal data from the Religious Orders
Study-Memory and Aging Project (ROSMAP) studies. First, we will use logistic regression models with
generalized estimating equations to assess differences in the associations between each survey question and
prevalent versus incident dementia. Second, we will assess the impact of improvements to dementia
algorithms for use in longitudinal time-to-event models for the association between diabetes and dementia risk.
Fellowship Training: Emma Nichols is a PhD student in the Department of Epidemiology at the Johns
Hopkins Bloomberg School of Public Health. Through mentored research, coursework, and professional ...

## Key facts

- **NIH application ID:** 10460806
- **Project number:** 1F31AG074599-01A1
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Emma Nichols
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $31,376
- **Award type:** 1
- **Project period:** 2022-09-01 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10460806

## Citation

> US National Institutes of Health, RePORTER application 10460806, The effects of study design characteristics on dementia assessment: Recommendations for future epidemiologic studies (1F31AG074599-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10460806. Licensed CC0.

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