The increased purchase of asthma medication for individuals born preterm seems to wane with age: A register-based longitudinal national cohort study.

The strong association between gestational age and purchase of prescription asthma medication weakens with age into early adulthood, in consistence with the results from our previous study. The risk for purchasing medication to treat asthma-like symptoms was higher in more recent birth years, but the effect of gestational age was small beyond 11 years of age. Gestational age per se did not seem to be significant for the development of asthma-like symptoms: most of its effect could be explained by other perinatal factors.