Related Experiment Videos
Association between asthma and family size between 1977 and 1994
R J Rona1, J M Hughes, S Chinn
1Department of Public Health Medicine, UMDS, London.
Journal of Epidemiology and Community Health
|May 18, 1999
Summary
This study found that while the overall link between asthma and family size hasn't significantly changed over time, only children show a higher prevalence. Asthma rates have disproportionately increased among lower social classes.
Area of Science:
- Epidemiology
- Pediatric Allergy
- Public Health
Background:
- Recent studies suggest a negative association between asthma and family size or birth order.
- Previous data from 10-30 years ago did not detect this association.
- This study investigates changes in this association over time.
Purpose of the Study:
- To compare the association between sibship size and asthma across three surveys conducted in 1977, 1985/86, and 1993/94.
- To examine trends in asthma prevalence related to family size and birth order.
- To identify potential shifts in asthma epidemiology over time.
Main Methods:
- Cross-sectional comparison of three large-scale surveys in England and Scotland.
- Involved approximately 9000 children aged 5-11 years in each survey.
- Data collected via parental reports on asthma, bronchitis attacks, and wheeze in the past 12 months.
Main Results:
- No significant overall association between asthma and total number of siblings (p = 0.22).
- Only children exhibited a higher prevalence of asthma compared to children with siblings (OR 0.87, 95% CI 0.76 to 0.98).
- A significant interaction between social class and survey year was detected (p = 0.004), with higher asthma prevalence in lower social classes in 1993/94.
Conclusions:
- Provides marginal support for a change over time in the sibship size-asthma association.
- The specific exposure agent explaining the association remains controversial.
- Suggests a disproportionate increase in asthma prevalence within lower social classes over the study period.