Children's Health: Sticking with asthma medication doesn't guarantee good results

Researchers have made the seemingly contradictory observation that children who use their inhaler more consistently have poorer control of their asthma.

The study involved more than 900 children with mild to moderate asthma, 425 of whom were advised to take inhaled corticosteroid medication, which decreases inflammation of the breathing passages.

Over the next four years, children who reported consistent medication use were 60 per cent more likely to report poorly controlled asthma compared with children who did not report regular medication use -- even after the researchers accounted for the severity of the asthma.

Poor asthma control was defined as asthma symptoms causing more than one nighttime awakening in the previous week, having more than two days where activity was limited in the previous week, or more than two days using a "rescue" inhaler to open constricted breathing passages in the previous week.

Study author Dr. Gregory Sawicki of Children's Hospital Boston says it is possible that inhaled corticosteroids work better in some children than in others, and his research team is planning to look for genetic factors that could explain these differences. "Although inhaled steroids are the main therapy for asthma, and should remain so with all children with persistent asthma, there is likely to be a subgroup of children who don't respond appropriately to inhaled steroid therapy."

However, he cautions that potential weaknesses in the study could also explain the findings: Though the researchers did their best to adjust for asthma severity, children who were advised to be on inhaled corticosteroids likely had more severe asthma at the beginning of the study. And secondly, medication adherence was not measured by the researchers, but rather self-reported by the children and their parents, which could lead to inaccuracies.