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Multiple pathologies are common and related to dementia in the oldest-old: The 90+ Study
Kawas CH, Kim RC, Sonnen JA, Bullain SS, Trieu T, Corrada MM.. Neurology, 2015-07-15
Topic: Risk, prevention and care in population studies
Objective The purpose of this study was to examine the role of multiple pathologies in the expression of dementia in the oldest-old. Methods A total of 183 participants of The 90+ Study with longitudinal follow-up and autopsy were included in this clinical-pathologic investigation. Eight pathologic diagnoses (Alzheimer disease [AD], microinfarcts, hippocampal sclerosis, macroinfarcts, Lewy body disease, cerebral amyloid angiopathy, white matter disease, and others) were dichotomized. We estimated the odds of dementia in relation to each individual pathologic diagnosis and to the total number of diagnoses. We also examined dementia severity in relation to number of pathologic diagnoses. Results The presence of multiple pathologic diagnoses was common and occurred more frequently in those with dementia compared with those without dementia (45% vs 14%). Higher numbers of pathologic diagnoses were also associated with greater dementia severity. Participants with intermediate/high AD pathology alone were 3 times more likely to have dementia (odds ratio = 3.5), but those with single non-AD pathologies were 12 times more likely to have dementia (odds ratio = 12.4). When a second pathology was present, the likelihood of dementia increased 4-fold in those with intermediate/high AD pathology but did not change in those with non-AD pathologies, suggesting that pathologies may interrelate in different ways. Conclusions In the oldest-old, the presence of multiple pathologies is associated with increased likelihood and severity of dementia. The effect of the individual pathologies may be additive or perhaps synergistic and requires further research. Multiple pathologies will need to be targeted to reduce the burden of dementia in the population.
Key findings
- Results The presence of multiple pathologic diagnoses was common and occurred more frequently in those with dementia compared with those without dementia (45% vs 14%).
- Higher numbers of pathologic diagnoses were also associated with greater dementia severity.
- When a second pathology was present, the likelihood of dementia increased 4-fold in those with intermediate/high AD pathology but did not change in those with non-AD pathologies, suggesting that pathologies may interrelate in different ways.
- Conclusions In the oldest-old, the presence of multiple pathologies is associated with increased likelihood and severity of dementia.
Why it matters
In 183 members of The 90+ Study who were followed during life and examined at autopsy, having more than one brain pathology was common and was found in 45% of those with dementia versus 14% of those without; more pathologies went with more severe dementia. Adding a second pathology was linked to a four-fold rise in the likelihood of dementia among people with intermediate/high Alzheimer pathology, but not among those with other pathologies, which the authors say suggests "pathologies may interrelate in different ways." These are autopsy-based associations in people aged 90 and over; the study does not test any treatment or prevention.
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Study details
- Study designlongitudinal study
- Participants183
- Evidence strengthModerate
How this study scored 68/100
Published in a leading specialty journal, and it is a longitudinal study following the same people over time. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A longitudinal study following the same people over time |
| 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 | 2015 — within 20 year(s) of the newest study here |
| Sample size | 2 / 4 | 183 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| 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 | 6 / 7 | Cited 303 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 23.3 citations a year over 13 year(s) since 2015 |
| Impact for its field and year | 4 / 6 | Cited 16.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 32 other studies in this library |
| Still being cited | 3 / 4 | Cited 75 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author María M. Corrada: h-index 55 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Utah: institution h-index 1,238 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 4 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 26180144) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 68 / 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. Check the citation against the original before you use it.
APA 7th
Kawas, C. H., Kim, R. C., Sonnen, J. A., Bullain, S. S., Trieu, T., & Corrada, M. M. (2015). Multiple pathologies are common and related to dementia in the oldest-old: The 90+ Study. Neurology. https://doi.org/10.1212/wnl.0000000000001831
Vancouver
Kawas CH, Kim RC, Sonnen JA, Bullain SS, Trieu T, Corrada MM. Multiple pathologies are common and related to dementia in the oldest-old: The 90+ Study. Neurology. 2015. doi:10.1212/wnl.0000000000001831. PMID: 26180144.
BibTeX
@article{kawas2015-26180144,
author = {Kawas, C. H. and Kim, R. C. and Sonnen, J. A. and Bullain, S. S. and Trieu, T. and Corrada, M. M.},
title = {{Multiple pathologies are common and related to dementia in the oldest-old: The 90+ Study}},
journal = {Neurology},
year = {2015},
doi = {10.1212/wnl.0000000000001831},
pmid = {26180144},
url = {https://doi.org/10.1212/wnl.0000000000001831}
}
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