The Canadian Childhood Asthma Primary Prevention Study: Outcomes at 7 Years of Age
Bibliographic record
Abstract
Purpose of the Study. To evaluate the effects of a multifaceted intervention program involving high-risk infants on the development of asthma at 7 years of age. Study Population. Of the original 545 high-risk infants in the Canadian Childhood Asthma Primary Prevention Study, 380 were evaluated at 7 years of age. Infants at high risk for asthma development were defined as those with at least 1 first-degree relative with asthma or 2 first-degree relatives with other immunoglobulin E–mediated allergic diseases. Methods. The initial 545 high-risk infants were randomly assigned before birth to a multifaceted intervention group (n = 279) or the control group (n = 266). The multifaceted intervention program, which was implemented before birth and during the first year of life, included house dust mite–control measures, pet-avoidance measures, avoidance of environmental tobacco smoke, breastfeeding, and/or using partially hydrolyzed whey formula. This study describes the follow-up assessment of 380 subjects at 7 years of age who completed a questionnaire and were evaluated by a pediatric allergist for asthma. Allergy skin testing and methacholine challenge were also performed. Results. A significantly lower number of subjects had pediatric allergist–diagnosed asthma in the intervention group (14.9%) than in the control group (23.0%; adjusted relative risk [RR]: 0.44). The prevalence of asthma, defined as wheeze plus bronchial hyperreactivity (methacholine challenge), was also significantly lower in the intervention group when compared with the control group (12.9% vs 25%, respectively; adjusted RR: 0.39). There was no significant difference in the diagnosis of allergic rhinitis or atopic dermatitis, allergen skin-test reactivity, or bronchial hyperreactivity alone between the 2 groups. Symptoms of wheeze and wheeze apart from colds in the last 12 months were significantly lower in the intervention group compared with the control group. There were no significant differences in nocturnal symptoms, exercise-related symptoms, medication use, emergency visits for wheeze, nasal symptoms, or skin rash. Reviewer Comments. Asthma and allergic diseases likely result from a combination of environmental and genetic factors. This study showed that the prevalence of asthma was decreased after an intervention program implemented early in life. Thus, recommending environmental controls as a safe method to decrease the risk of developing asthma in high-risk patients is reasonable. It is unclear from this study whether a specific environmental control or a combination of interventions is more effective. It is interesting that no difference was noted in the prevalence of allergic rhinitis or atopic dermatitis between the groups, which, theoretically, could also be affected by environmental controls.
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.003 |
| Science and technology studies | 0.003 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 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".