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Geographical variation in dementia: systematic review with meta-analysis
Russ TC, Batty GD, Hearnshaw GF, Fenton C, Starr JM.. International journal of epidemiology, 2012-07-13
Topic: Risk, prevention and care in population studies
Background Geographical variation in dementia prevalence and incidence may indicate important socio-environmental contributions to dementia aetiology. However, previous comparisons have been hampered by combining studies with different methodologies. This review systematically collates and synthesizes studies examining geographical variation in the prevalence and incidence of dementia based on comparisons of studies using identical methodologies. Methods Papers were identified by a comprehensive electronic search of relevant databases, scrutinising the reference sections of identified publications, contacting experts in the field and re-examining papers already known to us. Identified articles were independently reviewed against inclusion/exclusion criteria and considered according to geographical scale. Rural/urban comparisons were meta-analysed. Results Twelve thousand five hundred and eighty records were reviewed and 51 articles were included. Dementia prevalence and incidence varies at a number of scales from the national down to small areas, including some evidence of an effect of rural living [prevalence odds ratio (OR) = 1.11, 90% confidence interval (CI) 0.79-1.57; incidence OR = 1.20, 90% CI 0.84-1.71]. However, this association of rurality was stronger for Alzheimer disease, particularly when early life rural living was captured (prevalence OR = 2.22, 90% CI 1.19-4.16; incidence OR = 1.64, 90% CI 1.08-2.50). Conclusions There is evidence of geographical variation in rates of dementia in affluent countries at a variety of geographical scales. Rural living is associated with an increased risk of Alzheimer disease, and there is a suggestion that early life rural living further increases this risk. However, the fact that few studies have been conducted in resource-poor countries limits conclusions.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Russ, T. C., Batty, G. D., Hearnshaw, G. F., Fenton, C., & Starr, J. M. (2012). Geographical variation in dementia: systematic review with meta-analysis. International journal of epidemiology. https://doi.org/10.1093/ije/dys103
Vancouver
Russ TC, Batty GD, Hearnshaw GF, Fenton C, Starr JM. Geographical variation in dementia: systematic review with meta-analysis. International journal of epidemiology. 2012. doi:10.1093/ije/dys103. PMID: 22798662.
BibTeX
@article{russ2012-22798662,
author = {Russ, T. C. and Batty, G. D. and Hearnshaw, G. F. and Fenton, C. and Starr, J. M.},
title = {{Geographical variation in dementia: systematic review with meta-analysis}},
journal = {International journal of epidemiology},
year = {2012},
doi = {10.1093/ije/dys103},
pmid = {22798662},
url = {https://doi.org/10.1093/ije/dys103}
}
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.
Key findings
- Results Twelve thousand five hundred and eighty records were reviewed and 51 articles were included.
- Rural living is associated with an increased risk of Alzheimer disease, and there is a suggestion that early life rural living further increases this risk.
Why it matters
This meta-analysis found that rural living is associated with an increased risk of Alzheimer's disease, with a suggestion that early life rural living further increases this risk. It identifies a possible socio-environmental contribution to dementia but does not test any treatment or prevention.
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Study details
- Study designmeta-analysis
- Effect sizeOR = 1.20; OR = 2.22; OR = 1.64
- Evidence strengthHigh
How this study scored 63/100
Published in a peer-reviewed journal, and it is a meta-analysis pooling many studies. Scored zero for sample size and studied in people because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (International journal of epidemiology) |
| Journal's citation record | 3 / 4 | International Journal of Epidemiology: journal h-index 328 (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 | 1 / 5 | 2012 — within 20 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 5 / 7 | Cited 193 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 12.1 citations a year over 16 year(s) since 2012 |
| Impact for its field and year | 2 / 6 | Cited 1.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 19 other studies in this library |
| Still being cited | 2 / 4 | Cited 45 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author John M. Starr: h-index 46 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University College London: institution h-index 2,029 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 22798662) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 63 / 100 | — |
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Read the original
- DOI: 10.1093/ije/dys103
- PubMed: 22798662
- Original source →
- Free full text: Edinburgh Research Explorer (University of Edinburgh) →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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