SynthesisPloS one2017
Effect of outdoor air pollution on asthma exacerbations in children and adults: Systematic review and multilevel meta-analysis.
Synthesis in PloS one, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 208 papers, 8 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
208 citing papers in PubMed, 8 syntheses or guidelines pooled it, 434 citations in OpenAlex.
- Association Between Air Pollution and Childhood Asthma: A Systematic Review of Recent Evidence.Advances in respiratory medicine · 2026Pooled it
- Update of a systematic review on associations between environmental exposures and asthma control and exacerbations in young children.BMJ open · 2025Pooled it
- Association between air pollution and allergic upper respiratory diseases: a meta-analysis.European respiratory review : an official journal of the European Respiratory Society · 2025Pooled it
- Lifetime air pollution exposure, cognitive deficits, and brain imaging outcomes: A systematic review.Neurotoxicology · 2023Pooled it
- Effects of air pollution on restricted activity days: systematic review and meta-analysis.Environmental health : a global access science source · 2023Pooled it
- Are the adverse health effects of air pollution modified among active children and adolescents? A review of the literature.Preventive medicine · 2022Pooled it
- The long-term effect of exposure to respirable particulate matter on the incidence of myocardial infarction: a systematic review and meta-analysis study.Environmental science and pollution research international · 2022Pooled it
- Interactive effects of allergens and air pollution on respiratory health: A systematic review.The Science of the total environment · 2021Pooled it
- Trial
- Proximity to major roadways and asthma symptoms in the School Inner-City Asthma Study.The Journal of allergy and clinical immunology · 2020Trial
- Health effects of air pollution on chronic respiratory diseases.The Korean journal of internal medicine · 2026Review
- Climate change, environmental exposures, and pediatric asthma exacerbations: air pollution, temperature, and relative humidity.Pediatric research · 2026Review
- The impact of neighbourhood material and social disadvantage on respiratory health across Canada.The European respiratory journal · 2026Article
- Comparison of personal portable and fixed-site PMScientific reports · 2026Article
- Impact of PMJournal of environmental health science & engineering · 2026Article
- Asthma exacerbation risk after short-term air pollution exposure varies by age, sex, severity, and eosinophil count: East London cohort study.Respiratory research · 2026Article
- Review
- Impact of air pollution on exacerbations of respiratory and cardiovascular diseases for the intensivist: a narrative review.Intensive care medicine experimental · 2026Review
- A Review of the Increasing Impact and Effects of Air Pollution Throughout Life and Before Birth.Medical science monitor : international medical journal of experimental and clinical research · 2026Review
- Air Pollution, COVID-19-related Air-quality Changes, and Premature Mortality in Türkiye (2019-2023).Thoracic research and practice · 2026Article
148 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundSeveral observational studies have suggested that outdoor air pollution may induce or aggravate asthma. However, epidemiological results are inconclusive due to the presence of numerous moderators which influence this association. The goal of this study was to assess the relationship between outdoor air pollutants and moderate or severe asthma exacerbations in children and adults through a systematic review and multilevel meta-analysis. MATERIAL AND
methodsWe searched studies published in English on PubMed, Scopus, and Google Scholar between January 2000 and October 2016. Studies following a case-crossover design with records of emergency departments and/or hospital admissions as a surrogate of moderate or severe asthma exacerbations were selected. A multilevel meta-analysis was employed, taking into account the potential clustering effects within studies examining more than one lag. Odds ratios (ORs) and 95% confidence intervals were estimated. A subgroup analysis in children aged 0 to 18 years and a sensitivity analysis based on the quality of the included studies as defined in the Newcastle-Ottawa Scale were performed. Publication bias was evaluated through visual inspection of funnel plots and by a complementary search of grey literature. (Prospero Registration number CRD42015032323).
resultsDatabase searches retrieved 208 records, and finally 22 studies were selected for quantitative analysis. All pollutants except SO2 and PM10 showed a significant association with asthma exacerbations (NO2: 1.024; 95% CI: 1.005,1.043, SO2: 1.039; 95% CI: 0.988,1.094), PM10: 1.024; 95% CI: 0.995,1.053, PM2.5: 1.028; 95% CI: 1.009,1.047, CO: 1.045; 95% CI: 1.005,1.086, O3: 1.032; 95% CI: 1.005,1.060. In children, the association was significant for NO2, SO2 and PM2.5.
conclusionThis meta-analysis provides evidence of the association between selected air pollutants and asthma exacerbations for different lags.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.