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Prevalence of dementia in the United States: the aging, demographics, and memory study
Plassman BL, Langa KM, Fisher GG, Heeringa SG, Weir DR, Ofstedal MB, Burke JR, Hurd MD et al.. Neuroepidemiology, 2007-10-29
Topic: Risk, prevention and care in population studies
Aim To estimate the prevalence of Alzheimer's disease (AD) and other dementias in the USA using a nationally representative sample. Methods The Aging, Demographics, and Memory Study sample was composed of 856 individuals aged 71 years and older from the nationally representative Health and Retirement Study (HRS) who were evaluated for dementia using a comprehensive in-home assessment. An expert consensus panel used this information to assign a diagnosis of normal cognition, cognitive impairment but not demented, or dementia (and dementia subtype). Using sampling weights derived from the HRS, we estimated the national prevalence of dementia, AD and vascular dementia by age and gender. Results The prevalence of dementia among individuals aged 71 and older was 13.9%, comprising about 3.4 million individuals in the USA in 2002. The corresponding values for AD were 9.7% and 2.4 million individuals. Dementia prevalence increased with age, from 5.0% of those aged 71-79 years to 37.4% of those aged 90 and older. Conclusions Dementia prevalence estimates from this first nationally representative population-based study of dementia in the USA to include subjects from all regions of the country can provide essential information for effective planning for the impending healthcare needs of the large and increasing number of individuals at risk for dementia as our population ages.
Key findings
- Results The prevalence of dementia among individuals aged 71 and older was 13.9%, comprising about 3.4 million individuals in the USA in 2002.
Why it matters
Based on in-home assessments of 856 people aged 71 and older drawn from the nationally representative Health and Retirement Study, this study estimated that 13.9% of that age group in the USA (about 3.4 million people) had dementia in 2002, and 9.7% (about 2.4 million) had Alzheimer's disease. Dementia was far more common with age: 5.0% at ages 71–79 against 37.4% at 90 and older. These are weighted national estimates from a single snapshot, intended for planning care needs; the study did not test any cause or treatment.
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Study details
- Participants856
- Effect size13.9%; 9.7%; 5.0%
- Evidence strengthLow
How this study scored 62/100
Published in a peer-reviewed journal. Scored zero for study design and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Neuroepidemiology) |
| Journal's citation record | 1 / 4 | Neuroepidemiology: journal h-index 125 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2007 — within 20 year(s) of the newest study here |
| Sample size | 2 / 4 | 856 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 7 / 7 | Cited 1,938 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 92.3 citations a year over 21 year(s) since 2007 |
| Impact for its field and year | 5 / 6 | Cited 34.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 5 / 6 | Cited by 116 other studies in this library |
| Still being cited | 3 / 4 | Cited 181 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Robert B. Wallace: h-index 132 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Michigan: institution h-index 2,240 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 6 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 17975326) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 62 / 100 | — |
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Read the original
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APA 7th
Plassman, B. L., Langa, K. M., Fisher, G. G., Heeringa, S. G., Weir, D. R., Ofstedal, M. B., et al. (2007). Prevalence of dementia in the United States: the aging, demographics, and memory study. Neuroepidemiology. https://doi.org/10.1159/000109998
Vancouver
Plassman BL, Langa KM, Fisher GG, Heeringa SG, Weir DR, Ofstedal MB, et al. Prevalence of dementia in the United States: the aging, demographics, and memory study. Neuroepidemiology. 2007. doi:10.1159/000109998. PMID: 17975326.
BibTeX
@article{plassman2007-17975326,
author = {Plassman, B. L. and Langa, K. M. and Fisher, G. G. and Heeringa, S. G. and Weir, D. R. and Ofstedal, M. B. and Burke, JR. and Hurd, M. D. and others},
title = {{Prevalence of dementia in the United States: the aging, demographics, and memory study}},
journal = {Neuroepidemiology},
year = {2007},
doi = {10.1159/000109998},
pmid = {17975326},
url = {https://doi.org/10.1159/000109998}
}
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