Adult-onset asthma becomes the dominant phenotype among women by age 40 years. the longitudinal CARDIA study.

Rationale: Although asthma is usually considered to originate in childhood, adult-onset disease is being increasingly reported.

Objectives: To contrast the proportion and natural history of adult-onset versus pediatric-onset asthma in a community-based cohort. We hypothesized that asthma in women is predominantly of adult onset rather than of pediatric onset.