Generational Patterns of Asthma Incidence among Immigrants to Canada over Two Decades. A Population-based Cohort Study
Bibliographic record
Abstract
Abstract Rationale Canada, an industrialized country with high endemic asthma rates, is characterized by a large immigrant population. Objectives We sought to provide insight into the relative contribution of environmental exposure to asthma risk by comparing asthma rates among recent immigrants relative to long-term residents of Canada. Methods This was a population-based, retrospective cohort study performed using provincial health administrative data for all residents of Ontario, Canada. Residents with and without a diagnosis of asthma from fiscal years 1996–2012 were included. Individuals were categorized as being immigrants (landed in Canada after 1985) or long-term residents of Ontario by linkage with the Immigration, Refugees, and Citizenship Canada’s Permanent Resident Database. We calculated the age- and sex-standardized incidence of asthma among residents of Ontario, and compared the incidence of asthma among immigrants and long-term residents using incidence rate ratios (IRRs). Results Analysis of approximately 11.7 million records showed that 2.2 immigrants arrived in Canada during the study period, with over 50% from East and South Asia and the Pacific. We found that asthma incidence was lower among immigrants compared with long-term residents (IRR = 0.30; 95% confidence interval = 0.30–0.30; P < 0.001). However, Ontario-born children of immigrants from most world regions had significantly higher asthma incidence compared with children of long-term residents (IRR = 1.44; 95% confidence interval = 1.43–1.45; P < 0.001). The overall incidence of asthma in Ontario decreased between 1996 and 2012 (P trend < 0.001). Immigrants contributed to only a small proportion of the asthma incidence in Ontario, and changes within this group did not significantly affect trends in the overall Ontario population asthma incidence. Conclusions The higher asthma incidence seen among children of immigrants, but not in their parents, suggests that being born in Canada was critical for determining asthma risk. These findings support the importance of in utero and/or early life exposures on asthma development.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".