PURPOSE OF THE STUDY.
The goal of this study was to evaluate the risk of a child developing asthma if 1 or both parents has asthma.
A random sample of 1623 children was followed up over 20 years. The outcome of interest was physician-diagnosed asthma in parents or children determined by telephone interview at baseline and follow-up surveys.
If either of the parents had asthma, the risk of the child developing asthma was significantly increased throughout the study period: the maternal asthma hazard ratio (HR) was 1.91 (95% confidence interval [CI]: 1.36–2.69), and the paternal asthma HR was 2.01 (95% CI: 1.37–2.96). The risk was higher still if both parents had asthma (HR: 3.83 [95% CI: 2.03–7.24]). Siblings conveyed a strong independent risk for the study subject to develop asthma (HR: 2.33 [95% CI: 1.73–3.14]). This risk was even higher when more than one-half of the subject’s siblings had asthma, indicating a dose–response pattern (HR: 2.92 [95% CI: 1.94–4.41]).
The results underline the usefulness of asking about asthma in siblings in addition to parental asthma in clinical practice.
We have long known that asthma runs in families. This study helps clarify the risk. If both parents have asthma, the child's risk of developing asthma is greater than if only 1 parent has asthma, and, furthermore, this risk of developing asthma continues into adolescence and young adulthood. Having siblings with asthma also increases the risk even if neither parent has asthma.
- Copyright © 2014 by the American Academy of Pediatrics