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54/100

✓ Peer-reviewed alzhub usefulness score 54 out of 100. Risk factors

Topic: Risk, prevention and care in population studies

Plain-language summary

The average PM2.5 levels in the IHS counties were lower than those in all US counties, while the mean O3 levels in the IHS counties were higher than the US counties. Multivariable Cox regressions revealed a positive association between dementia and county-level O3 with a hazard ratio of 1.24 (95% CI: 1.02–1.50) per 1 ppb standardized O3. PM2.5 and NO2 were not associated with dementia risk after adjusting for all covariates. (4) O3 is associated with a higher risk of dementia among American Indians.

What this study adds

Evidence grade: Moderate

This is a follow-up (cohort) study of 26,871 participants. In a cohort of American Indians aged 55 and older, higher county-level ozone was associated with a higher risk of dementia, while PM2.5 and NO2 were not associated with dementia risk after adjusting for all covariates. This is an observational link between air pollution and dementia risk, so it cannot show that reducing ozone would prevent dementia.

Taken from this record’s own fields, not from reading the paper. The grade is assigned from the abstract’s wording; what that means.

Cite this study APA, Vancouver, BibTeX · download .bib or .ris

APA 7th

Zhu, Y., Shi, Y. V., Bartell, S. M., Corrada, M. M., Manson, S. M., O’Connell, J. M., et al. (2024). Potential Effects of Long-Term Exposure to Air Pollution on Dementia: A Longitudinal Analysis in American Indians Aged 55 Years and Older. International Journal of Environmental Research and Public Health. https://doi.org/10.3390/ijerph21020128

Vancouver

Zhu Y, Shi YV, Bartell SM, Corrada MM, Manson SM, O’Connell JM, et al. Potential Effects of Long-Term Exposure to Air Pollution on Dementia: A Longitudinal Analysis in American Indians Aged 55 Years and Older. International Journal of Environmental Research and Public Health. 2024. doi:10.3390/ijerph21020128. PMID: 38397619.

BibTeX

@article{zhu2024-38397619,
  author  = {Zhu, Yachen and Shi, Yuxi Vania and Bartell, Scott M. and Corrada, María M. and Manson, Spero M. and O’Connell, Joan M. and Jiang, Luohua},
  title   = {{Potential Effects of Long-Term Exposure to Air Pollution on Dementia: A Longitudinal Analysis in American Indians Aged 55 Years and Older}},
  journal = {International Journal of Environmental Research and Public Health},
  year    = {2024},
  doi     = {10.3390/ijerph21020128},
  pmid    = {38397619},
  url     = {https://doi.org/10.3390/ijerph21020128}
}

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 names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.

How to read this study

Design: this is a follow-up (cohort) study. People are observed over time and not assigned to anything, so an association can reflect other differences between groups. Look at how long follow-up lasted, how many dropped out, and whether the authors adjusted for age, education and other health conditions.
Size: the record lists 26,871 participants. Ask whether that is enough for the question, and who they were.
Effect: the record gives no effect size, so the summary above cannot say how large any difference was.

What the evidence grade means here

This page is graded moderate. alzhub.org assigns the grade automatically from keywords in the abstract, not from reading the paper. Moderate means the abstract mentions a cohort, case-control or longitudinal design. It can add at most 5 of the 100 points in the study score, and it is a label about design, not a verdict on whether the findings are true.

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Key findings

The average PM2.5 levels in the IHS counties were lower than those in all US counties, while the mean O3 levels in the IHS counties were higher than the US counties.
Multivariable Cox regressions revealed a positive association between dementia and county-level O3 with a hazard ratio of 1.24 (95% CI: 1.02–1.50) per 1 ppb standardized O3.
PM2.5 and NO2 were not associated with dementia risk after adjusting for all covariates.
(4) O3 is associated with a higher risk of dementia among American Indians.

Why it matters

In a cohort of American Indians aged 55 and older, higher county-level ozone was associated with a higher risk of dementia, while PM2.5 and NO2 were not associated with dementia risk after adjusting for all covariates. This is an observational link between air pollution and dementia risk, so it cannot show that reducing ozone would prevent dementia.

New to this subject? Start with our plain-English guide: Risk factors, ranked →

Study details

Study designcohort study
Participants26,871
Evidence strengthModerate

How this study scored 54/100

Published in a peer-reviewed journal, and it is a cohort study following people over time. Scored zero for effect reported and randomized / blinded because the record does not state it.

Component	Points	Why
Journal tier	7 / 10	Tier 3 — peer-reviewed journal (International Journal of Environmental Research and Public Health)
Journal's citation record	3 / 4	International Journal of Environmental Research and Public Health: journal h-index 320 (OpenAlex, 2026-10-29)
Study design	7 / 12	A cohort study following 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	4 / 5	2024 — within 3 year(s) of the newest study here
Sample size	4 / 4	26,871 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)
Randomized / blinded	0 / 2	No randomization or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	2 / 7	Cited 5 times (OpenAlex, 2026-10-10)
Citations per year	1 / 5	1.2 citations a year over 4 year(s) since 2024
Impact for its field and year	1 / 6	Cited 0.8× the average for papers of its field and year (OpenAlex FWCI)
Cited by studies here	0 / 6	No other study in this library cites it
Still being cited	1 / 4	Cited 5 times in 2024–2026 (2026 still in progress; OpenAlex)
Senior author's track record	2 / 4	Last-listed author Luohua Jiang: h-index 35 (OpenAlex, whole career)
Institution's track record	1 / 3	University of California, Irvine: institution h-index 1,195 (OpenAlex)
Multicenter collaboration	1 / 3	OpenAlex lists 3 institution(s) in 1 country
Indexed in PubMed	2 / 2	Indexed in PubMed (PMID 38397619)
Free to read	2 / 2	Free to read
Total	54 / 100	—

What each of these 20 components measures, and what this score is not →

Read the original

Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).

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