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Epidemiology of dementia in Nigeria: results from the Indianapolis-Ibadan study
Ogunniyi A, Baiyewu O, Gureje O, Hall KS, Unverzagt F, Siu SH, Gao S, Farlow M et al.. European journal of neurology, 2000-09-01
Topic: Risk, prevention and care in population studies
We determined the prevalence of dementia in a cohort of 2494 elderly Nigerians residents in Idikan Community, Ibadan, Nigeria. We utilized the Community Screening Instrument for Dementia to select subjects for clinical assessment in the second stage. The findings were compared with those of 2212 African Americans living in Indianapolis, studied simultaneously using similar methodology. The overall age-adjusted prevalence rates of dementia and Alzheimer's disease in Ibadan were 2.29% and 1.41%, respectively. These rates were much lower than the respective values of 8.24% and 6.24% obtained for African Americans. In Ibadan, Alzheimer's disease accounted for 64.3% of the cases, with old age and female gender being the significant risk factors, whilst 'living with others' appeared to be protective (P < 0.05). Amongst African Americans, on the other hand, old age, rural living below the age of 19 years, low educational attainment and family history of dementia were the risk factors. There was a lack of association between Alzheimer's disease and possession of the apolipoprotein E epsilon4 allele in the Nigerian sample, unlike the finding in African Americans, where significant association was shown. In addition, the frequencies of the vascular risk factors investigated were lower in Nigerians. Our results showed lower prevalence of dementia and Alzheimer's disease in Nigerians, compared with African Americans. There was no association between Alzheimer's disease and apolipoprotein E (epsilon4 allele) in the former. The differences in the frequencies of vascular risk factors between Nigerian subjects and African Americans would suggest involvement of environmental factors in disease process.
Key findings
- The findings were compared with those of 2212 African Americans living in Indianapolis, studied simultaneously using similar methodology.
- The overall age-adjusted prevalence rates of dementia and Alzheimer's disease in Ibadan were 2.29% and 1.41%, respectively.
- In Ibadan, Alzheimer's disease accounted for 64.3% of the cases, with old age and female gender being the significant risk factors, whilst 'living with others' appeared to be protective (P < 0.05).
- There was a lack of association between Alzheimer's disease and possession of the apolipoprotein E epsilon4 allele in the Nigerian sample, unlike the finding in African Americans, where significant association was shown.
- Our results showed lower prevalence of dementia and Alzheimer's disease in Nigerians, compared with African Americans.
Why it matters
This study found much lower prevalence of dementia and Alzheimer's disease in elderly Nigerians than in African Americans, and found no association between Alzheimer's disease and the apolipoprotein E epsilon4 allele in the Nigerian sample. It does not test any treatment, cure or prevention.
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Study details
- Effect size2.29%; 1.41%; 8.24%
- Evidence strengthModerate
How this study scored 44/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (European journal of neurology) |
| Journal's citation record | 2 / 4 | European Journal of Neurology: journal h-index 181 (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 | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2000 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| 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 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 4 / 7 | Cited 94 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 3.4 citations a year over 28 year(s) since 2000 |
| Impact for its field and year | 2 / 6 | Cited 2.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 10 other studies in this library |
| Still being cited | 1 / 4 | Cited 7 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Hugh C. Hendrie: h-index 76 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Indiana University School of Medicine: institution h-index 784 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 11054131) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 44 / 100 | — |
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Read the original
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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. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Ogunniyi, A., Baiyewu, O., Gureje, O., Hall, K. S., Unverzagt, F., Siu, S. H., et al. (2000). Epidemiology of dementia in Nigeria: results from the Indianapolis-Ibadan study. European journal of neurology. https://doi.org/10.1046/j.1468-1331.2000.00124.x
Vancouver
Ogunniyi A, Baiyewu O, Gureje O, Hall KS, Unverzagt F, Siu SH, et al. Epidemiology of dementia in Nigeria: results from the Indianapolis-Ibadan study. European journal of neurology. 2000. doi:10.1046/j.1468-1331.2000.00124.x. PMID: 11054131.
BibTeX
@article{ogunniyi2000-11054131,
author = {Ogunniyi, A. and Baiyewu, O. and Gureje, O. and Hall, K. S. and Unverzagt, F. and Siu, S. H. and Gao, S. and Farlow, M. and others},
title = {{Epidemiology of dementia in Nigeria: results from the Indianapolis-Ibadan study}},
journal = {European journal of neurology},
year = {2000},
doi = {10.1046/j.1468-1331.2000.00124.x},
pmid = {11054131},
url = {https://doi.org/10.1046/j.1468-1331.2000.00124.x}
}
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