Brief-interval telephone surveys of medication adherence and asthma symptoms in the Childhood Asthma Management Program Continuation Study.

BACKGROUND

Although it is known that most patients do not consistently take controller medications every day, the impact of nonadherence on asthma control is not well documented.

OBJECTIVE

To establish the relationship between medication adherence and symptom control in adolescents and young adults with asthma.

METHODS

A total of 756 adolescents and young adults diagnosed as having mild to moderate asthma on entry into the original study underwent 6 monthly telephone interviews as an ancillary project to the Childhood Asthma Management Program Continuation Study. Participants were queried about medication use and symptom control within each 1-month interview window. Strategies adopted to improve self-report accuracy included use of repeated interviews, confidential reporting to staff unknown to the participants, and use of questions focused on recent behavior.

RESULTS

Only participants who were consistently on inhaled corticosteroids (ICSs) for the entire 6-month study interval were included. Three groups of patients were contrasted: those not on ICSs (n = 420), those on ICSs with high adherence (> or = 75% of medication taken, n = 90), and those on ICSs with low/medium adherence (< 75% of medication taken, n = 148). Participants in the low/medium adherence group reported, on average, less symptom control and more variability in wheezing, awakening at night, missed activities, and beta2-agonist use during the 6-month period, although most in this group perceived their asthma to be under good control.

CONCLUSION

Despite extensive patient education and support, diminished ICS adherence was frequent and undermined symptom control in this group of adolescents and young adults with mild to moderate asthma.