Residential exposures are recognized risk factors for asthma, but the relative contribution
of specific indoor allergens and their overall contribution to asthma among older
children and adolescents in the United States are unknown.
To estimate the relative contributions, population-attributable risks, and costs of
residential risk factors for doctor-diagnosed asthma. Design. Nationally representative,
cross-sectional survey conducted from 1988 to 1994.
A total of 5384 children who were 6 to 16 years old and participated in the National
Health and Nutrition Examination Survey III, a survey of the health and nutritional
status of children and adults in the United States.
Doctor-diagnosed asthma, as reported by the parent.
Five hundred three of 5384 children and adolescents (11.4%) had doctor-diagnosed asthma.
After adjusting for age, gender, race, urban status, region of country, educational
attainment of the head of household, and poverty, predictors of doctor-diagnosed asthma
included a history of allergy to a pet (odds ratio [OR: 2.4; 95% confidence interval
[CI]: 1.7, 3.3), presence of a pet in the household (OR: 1.5; 95% CI: 1.1, 2.1), and
immediate hypersensitivity to dust mite (OR: 1.5; 95% CI: 1.05, 2.0), Alternaria (OR:
1.9; 95% CI: 1.3, 2.8), and cockroach allergens (OR: 1.4; CI: 1.04, 1.9). Family history
of atopy (OR: 1.7; 95% CI: 1.1, 2.7) and diagnosis of allergic rhinitis (OR: 2.1;
CI: 1.1, 3.7) were also predictors for asthma. The population-attributable risk of
having 1 or more residential exposures associated with doctor-diagnosed asthma was
44.4% (95% CI: 29-60), or an estimated 2 million excess cases. The attributable cost
of asthma resulting from residential exposures was $405 million (95% CI: $264-$547
million) annually.
The elimination of identified residential exposures, if causally associated with asthma,
would result in a 44% decline in doctor-diagnosed asthma among older children and
adolescents in the United States.