Objective. To determine the risks associated with residential exposures for childhood asthma.
Study Population. Participants included 8257 children <6 years old who were enrolled in the Third National Health and Nutrition Examination Survey. This was a survey of the health and nutritional status of children and adults in the United States.
Methods. The study was a cross-sectional survey that was conducted from 1988 to 1994. The main outcome measure was doctor-diagnosed asthma, as reported by the parents.
Results. Six percent of children in the survey were reported by their parents to have doctor-diagnosed asthma. The prevalence of asthma was higher among boys (6.7%) than girls (5.1%) and among black children (8.9%) compared with white children (5.2%). Risk factors for doctor-diagnosed asthma included a family history of atopy (odds ratio [OR]: 2.2), child’s history of allergy to a pet (OR: 24.2), exposure to environmental tobacco smoke (OR: 1.8), use of gas stove or oven for heat (OR: 1.8), and the presence of a dog in the household (OR: 1.6). The population attributable risk of ≥1 residential exposure for doctor-diagnosed asthma in US children <6 years old was 39.2%, or an estimated 533 000 excess cases, while a positive family history of atopy accounted for 300 000. The attributable cost of asthma as a result of these residential exposures for children <6 years old was $402 million annually.
Conclusion. The elimination these identified residential risk factors could result in a 39% decline in doctor-diagnosed asthma in US children <6 years old.
Reviewer’s Comments. There has been a dramatic increase in asthma prevalence in the past 20 to 30 years. Although many factors certainly contributed to this increase, this study suggests that specific exposures in the homes of our patients may play a major role. Please note also that the presence of a dog in this study has a deleterious effects, contrary to the finding in the next study. The answer to the question of indoor pets is still far from clear, although this study and others clearly show that evidence of pet sensitivity are major risk factors for the diagnosis of asthma.
- Lanphear BP, Algine CA, Auinger P, Weitzman M, Byrd RS. Pediatrics.2001;107 :505– 511
- Copyright © 2002 by the American Academy of Pediatrics