Allergic diseases and asthma in the family predict the persistence and onset-age of asthma: a prospective cohort study (Respiratory Research)

Background: Family history of asthma and other allergic diseases have been linked to the risk of childhood asthma previously, but little is known about their effect on the age-of-onset and persistency of asthma until young adulthood. Methods: We assessed the effect of the family history of asthma and allergic diseases on persistent vs. transient, and early- vs. late-onset persistent asthma in The Espoo Cohort Study 1991?2011, a population-based cohort study of 1623 subjects (follow-up rate 63.2%). The determinants were any family history (any parent or sibling); maternal; paternal; siblings only; parents only; and both siblings and parents. Analyses were conducted separately for asthma and allergic diseases while taking the other disease into account as a confounding factor. The outcomes were persistent, transient, early-onset persistent(