Home › Research › Disparities
Ethnic Differences in Dementia Risk: A Systematic Review and Meta-Analysis
Shiekh SI, Cadogan SL, Lin LY, Mathur R, Smeeth L, Warren-Gash C.. Journal of Alzheimer's disease : JAD, 2021-01-01
Topic: Risk, prevention and care in population studies
Background Globally around 50 million people have dementia. Risk factors for dementia such as hypertension and diabetes are more common in Black, Asian, and other ethnic minorities. There are also marked ethnic inequalities in care seeking, likelihood of diagnosis, and uptake of treatments for dementia. Nevertheless, ethnic differences in dementia incidence and prevalence remain under-explored. Objective To examine published peer-reviewed observational studies comparing age-specific or age-adjusted incidence or prevalence rates of dementia between at least two ethnic groups. Methods We searched seven databases on 1 September 2019 using search terms for ethnicity, dementia, and incidence or prevalence. We included population-based studies comparing incidence or prevalence of dementia after accounting for age of at least two ethnic groups in adults aged 18 or more. Meta-analysis was conducted for eligible ethnic comparisons. Results We included 12 cohort studies and seven cross-sectional studies. Thirteen were from the US, and two studies each from the UK, Singapore, and Xinjiang Uyghur Autonomous Region in China. The pooled risk ratio for dementia incidence obtained from four studies comparing Black and White ethnic groups was 1.33 (95% CI 1.07-1.65; I-squared = 58.0%). The pooled risk ratio for dementia incidence comparing the Asian and White ethnic groups was 0.86 (95% CI 0.728-1.01; I-squared = 43.9%). There was no difference in the incidence of dementia for Latino ethnic group compared to the White ethnic group. Conclusion Evidence to date suggest there are ethnic differences in risk of dementia. Better understanding of the drivers of these differences may inform efforts to prevent or treat dementia.
Key findings
- Results We included 12 cohort studies and seven cross-sectional studies.
- There was no difference in the incidence of dementia for Latino ethnic group compared to the White ethnic group.
Why it matters
This systematic review and meta-analysis found a pooled risk ratio for dementia incidence of 1.33 comparing Black and White ethnic groups and 0.86 comparing Asian and White ethnic groups, with no difference for Latino compared to White ethnic groups. It is an observational review of ethnic differences in dementia risk, not evidence on treating, curing, or preventing Alzheimer's disease.
New to this subject? Start with our plain-English guide: Disparities →
Study details
- Study designmeta-analysis
- Participants12
- Effect size58.0%; 43.9%
- Evidence strengthHigh
How this study scored 66/100
Published in a peer-reviewed journal, and it is a meta-analysis pooling many studies.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of Alzheimer's disease : JAD) |
| Journal's citation record | 2 / 4 | Journal of Alzheimer s Disease: journal h-index 218 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A meta-analysis pooling many studies |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 3 / 5 | 2021 — within 6 year(s) of the newest study here |
| Sample size | 1 / 4 | 12 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 | A review of other studies — randomisation is not credited here |
| Times cited | 4 / 7 | Cited 82 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 11.7 citations a year over 7 year(s) since 2021 |
| Impact for its field and year | 2 / 6 | Cited 2.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 6 other studies in this library |
| Still being cited | 3 / 4 | Cited 56 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Charlotte Warren‐Gash: h-index 33 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | London School of Hygiene & Tropical Medicine: institution h-index 1,106 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 33554910) |
| Free to read | 2 / 2 | Free to read |
| Total | 66 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.3233/jad-201209
- PubMed: 33554910
- Original source →
- Free full text: Journal of Alzheimer s Disease →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Shiekh, S. I., Cadogan, S. L., Lin, L. Y., Mathur, R., Smeeth, L., & Warren-Gash, C. (2021). Ethnic Differences in Dementia Risk: A Systematic Review and Meta-Analysis. Journal of Alzheimer's disease : JAD. https://doi.org/10.3233/jad-201209
Vancouver
Shiekh SI, Cadogan SL, Lin LY, Mathur R, Smeeth L, Warren-Gash C. Ethnic Differences in Dementia Risk: A Systematic Review and Meta-Analysis. Journal of Alzheimer's disease : JAD. 2021. doi:10.3233/jad-201209. PMID: 33554910.
BibTeX
@article{shiekh2021-33554910,
author = {Shiekh, S. I. and Cadogan, S. L. and Lin, L. Y. and Mathur, R. and Smeeth, L. and Warren-Gash, C.},
title = {{Ethnic Differences in Dementia Risk: A Systematic Review and Meta-Analysis}},
journal = {Journal of Alzheimer's disease : JAD},
year = {2021},
doi = {10.3233/jad-201209},
pmid = {33554910},
url = {https://doi.org/10.3233/jad-201209}
}
Studies this one cites
Referenced by this study and also in the alzhub library, so you can read them here. Showing 12 of 16.
Later studies that cite this one
6 studies in the alzhub library list this one in their references.
Related studies in Disparities
Also tagged “prevalence”
1,224 studies in the library carry the topic tag “prevalence”; these are this study's neighbours in a fixed, alphabetical-by-hash tour of them, not the closest in content. All 1,224 tagged studies.