Cited by 191Dementia and Cognitive Impairment ResearchHealth disparities and outcomesAlzheimer's disease research and treatments

Geographical variation in dementia: Systematic review with meta-analysis

Open access
Russ, T. C., Batty, G. D., Hearnshaw, G. F., Fenton, C., Starr, J. M.·2012·International Journal of Epidemiology

Abstract

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.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1093/ije/dys103

Cites

140 of 140 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Part of this paper’s reference list could not be split into single entries.

Flagged first, then by citations

1 of the 141 references couldn’t be matched to a known paper.

Research works printed but not linked: 8

  1. Lobo A, Launer LJ, Fratiglioni L, et al. Prevalence of dementia and major subtypes in Europe: a collaborative study of population-based cohorts. Neurology 2000; 54: S4-S9.
  2. Sulkava R, Heliövaara M, Palo J, Wikström J, Aromaa A. Regional differences in the prevalence of Alzheimer's disease. In: Soininen H, editor. Proceedings of the International Symposium on Alzheimer's Disease, June 12-15, 1988, Kuopio, Finland. Department of Neurology, University of Kuopio, Finland: World Federation of Neurology Research Group on Dementia; 1988. p. 8.
  3. Yip P-K, Shyu Y-I, Liu S-I, et al. The multidisciplinary project of dementia study in northern Taiwan (DSNT): Background and methodology. Acta Neurol Taiwan 1997; 6: 210-6.
  4. Anzola-Perez E, Bangdiwala SI, De Llano GB, De La Vega ME, Dominguez O, Bern- Klug M. Towards community diagnosis of dementia: Testing cognitive impairment in older persons in Argentina, Chile and Cuba. Int J Geriatr Psych 1996; 11: 429-38.
  5. Laditka JN, Laditka SB, Cornman CB, Porter CN, Davis DR. High Variation in Both Alzheimer's Disease (AD) Prevalence and Factors Associated with Prevalence Suggest a Need for National AD Surveillance in the United States. 10th International Conference on Alzheimer's Disease and Related Disorders (ICAD 2006). Madrid, ; 2006.
  6. Laditka SB, Laditka JN, Cornman CB, Porter CN, Davis DR. Age-Specific Prevalence of Alzheimer's Disease in a U.S. State with High Population Risks: Is South Carolina a Harbinger of Future National Prevalence? 10th International Conference on Alzheimer's Disease and Related Disorders (ICAD 2006). Madrid, ; 2006.
  7. Hall K, Hendrie H, Brittain H, et al. The development of a dementia screening interview in two distinct languages. Int J Meth Psych Res 1993; 3: 1-28.
  8. Gauvreau D, Bouchard R, Gauthier S, et al. The IMAGE Project: a geographical laboratory for the investigation of multidisciplinary data. In: Sinet PM, Lamour Y, Christen Y, editors. Research and Perspectives in Alzheimer's Disease: Springer; 1988. p. 40-50.

Cited by

Sorted by citations

Authors
Russ, T. C., Batty, G. D., Hearnshaw, G. F., Fenton, C., & Starr, J. M.
Affiliations
  • National Health Service Scotland (GB)
  • University College London (GB)
Venue
International Journal of Epidemiology
Published
2012-07-13
Volume
41
Issue
4
Pages
1012-1032
ISSN
  • 0300-5771 (ISSN-L)
  • 1464-3685
OpenAlex
W2136224870
Cited by
191
References
141
Citations by year
2026: 6 · 2025: 17 · 2024: 21 · 2023: 20 · 2022: 19 · 2021: 18 · 2020: 14 · 2019: 11 · 2018: 12 · 2017: 12 · 2016: 12 · 2015: 9 · 2014: 12 · 2013: 6 · 2012: 2
FWCI
1.25
Type
journal article
Language
en
Open access
Locations
  • International Journal of Epidemiology (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Edinburgh Research Explorer (University of Edinburgh) (submittedVersion, other-oa)
  • UCL Discovery (University College London) (submittedVersion)
  • HighWire Press Open Archive (submittedVersion)
Funders
  • Wellcome Trust
  • Biotechnology and Biological Sciences Research Council
Topics
  • Health Sciences › Medicine › Psychiatry and Mental health › Dementia and Cognitive Impairment Research
  • Social Sciences › Health › Health disparities and outcomes
  • Health Sciences › Medicine › Physiology › Alzheimer's disease research and treatments
Keywords
dementia, regional variation, dementia prevalence, dementia incidence, urban-rural differences, rurality, Alzheimer's disease, socio-environmental risk factors, small area variation
MeSH terms
Dementia, Geography, Humans, Incidence, Prevalence

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review