Home › Research › Risk factors
Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research
Power MC, Adar SD, Yanosky JD, Weuve J.. Neurotoxicology, 2016-06-18
Topic: Air pollution and environmental exposures
Background Dementia is a devastating condition typically preceded by a long prodromal phase characterized by accumulation of neuropathology and accelerated cognitive decline. A growing number of epidemiologic studies have explored the relation between air pollution exposure and dementia-related outcomes. Methods We undertook a systematic review, including quality assessment, to interpret the collective findings and describe methodological challenges that may limit study validity. Articles, which were identified according to a registered protocol, had to quantify the association of an air pollution exposure with cognitive function, cognitive decline, a dementia-related neuroimaging feature, or dementia. Results We identified 18 eligible published articles. The quality of most studies was adequate to exemplary. Almost all reported an adverse association between at least one pollutant and one dementia-related outcome. However, relatively few studies considered outcomes that provide the strongest evidence for a causal effect, such as within-person cognitive or pathologic changes. Reassuringly, differential selection would likely bias toward a protective association in most studies, making it unlikely to account for observed adverse associations. Likewise, using a formal sensitivity analysis, we found that unmeasured confounding is also unlikely to explain reported adverse associations. Discussion We also identified several common challenges. First, most studies of incident dementia identified cases from health system records. As dementia in the community is underdiagnosed, this could generate either non-differential or differential misclassification bias. Second, almost all studies used recent air pollution exposures as surrogate measures of long-term exposure. Although this approach may be reasonable if the measured and etiologic exposure windows are separated by a few years, its validity is unknown over longer intervals. Third, comparing the magnitude of associations may not clearly pinpoint which, if any, pollutants are the probable causal agents, because the degree of exposure misclassification differs across pollutants. The epidemiologic evidence, alongside evidence from other lines of research, provides support for a relation of air pollution exposure to dementia. Future studies with improved design, analysis and reporting would fill key evidentiary gaps and provide a solid foundation for recommendations and possible interventions.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Power, M. C., Adar, S. D., Yanosky, J. D., & Weuve, J. (2016). Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research. Neurotoxicology. https://doi.org/10.1016/j.neuro.2016.06.004
Vancouver
Power MC, Adar SD, Yanosky JD, Weuve J. Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research. Neurotoxicology. 2016. doi:10.1016/j.neuro.2016.06.004. PMID: 27328897.
BibTeX
@article{power2016-27328897,
author = {Power, M. C. and Adar, S. D. and Yanosky, J. D. and Weuve, J.},
title = {{Exposure to air pollution as a potential contributor to cognitive function, cognitive decline, brain imaging, and dementia: A systematic review of epidemiologic research}},
journal = {Neurotoxicology},
year = {2016},
doi = {10.1016/j.neuro.2016.06.004},
pmid = {27328897},
url = {https://doi.org/10.1016/j.neuro.2016.06.004}
}
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 We identified 18 eligible published articles.
- Likewise, using a formal sensitivity analysis, we found that unmeasured confounding is also unlikely to explain reported adverse associations.
New to this subject? Start with our plain-English guide: Risk factors, ranked →
Study details
- Study designsystematic review
- Evidence strengthHigh
How this study scored 64/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for sample size, effect reported and studied in people because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 37 of the 58 points we could judge it on, which is 64 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Neurotoxicology) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 12 / 12 | A systematic review of all the studies on the question |
| 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 | 2016 — 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 | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| 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 | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 27328897) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 37 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 37 of the 58 points we could judge it on is 64 out of 100. |
| Total | 64 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Free copy unknown: no free-copy check has an answer for this record yet. That does not mean it is paywalled.
Related studies in Risk factors
Also tagged “air”
237 studies in the library carry the topic tag “air”; these are this study's neighbours in a fixed, alphabetical-by-hash tour of them, not the closest in content. All 237 tagged studies.