The two thirds with milder symptoms should grow out of asthma

Childhood asthma has been regarded as relatively benign and a condition that children often “grow out of.” Recently, however, investigators have reported higher prevalence of asthma in children1 2 and more frequent persistence of childhood asthma into adult life.3 Hence further studies on factors predicting remission or persistence of childhood asthma, and the development of adult asthma, are welcomed.

Two papers in this week's journal describe outcomes of asthma in cohorts of Australian children. Both longitudinal studies began in the 1960s and both followed up children recruited at age 7 until their 30s. One might therefore expect the findings of the two studies to be similar. Nevertheless, Jenkins et al conclude that “children with asthma reported by their parents were more likely than not to be free of symptoms as adults” (p 90)4 while Oswald et al conclude that “many children do not grow out of asthma” (p 95).5 How could similar studies in similar populations come to seemingly opposite conclusions?

Jenkins et al followed up a birth cohort of 8700 7 year old Tasmanian children whose parents had originally completed a questionnaire inquiring about a …