ArticleCMAJ open
Comparison of childhood asthma incidence in 3 neighbouring cities in southwestern Ontario: a 25-year longitudinal cohort study.
Article in CMAJ open. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers, 1 of them a synthesis 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
6 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Outdoor air pollutants and asthma risk in adolescents: evidence from a systematic review and meta-analysis.Frontiers in public health · 2025Pooled it
- Validation of a health administrative definition of obstructive sleep apnea in children in Ontario, Canada.PloS one · 2026Article
- The costs of suboptimal breastfeeding in Ontario, Canada, and potential healthcare resource impacts from improving rates: a pediatric health system costing analysis.International breastfeeding journal · 2025Article
- An inverse relationship between asthma prevalence and medication dispensation trend: a 12-year spatial analysis of electronic health record data in Alberta, Canada.ERJ open research · 2023Article
- Article
- The Burden of Childhood Asthma by Age Group, 1990-2019: A Systematic Analysis of Global Burden of Disease 2019 Data.Frontiers in pediatrics · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAir pollution is a known trigger for exacerbations among individuals with asthma, but its role in the development of new-onset asthma is unclear. We compared the rate of new asthma cases in Sarnia, a city with high pollution levels, with the rates in 2 neighbouring regions in southwestern Ontario, Canada.
methodsUsing a population-based birth cohort design and linked health administrative data, we compared the hazard of incident asthma among children 0 to 10 years of age between those born in Lambton (Sarnia) and those born in Windsor and London-Middlesex, for the period Apr. 1, 1993, to Mar. 31, 2009. We used Cox proportional hazards models to adjust for year of birth and exposure to air pollutants (nitrogen dioxide, sulphur dioxide [SO
resultsAmong 114 427 children, the highest incidence of asthma was in Lambton, followed by Windsor and London-Middlesex (30.3, 24.4 and 19.8 per 1000 person-years, respectively;
interpretationWe identified a higher incidence of asthma among children born in Lambton (Sarnia) relative to 2 other regions in southwestern Ontario. Higher levels of air pollution (particularly SO
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.