Factors related to lower adherence rates to inhaled corticosteroids in children and adolescents: a prospective randomized cohort study.

UNLABELLED: Asthma morbidity is high, partly due to low adherence to inhaled corticosteroids (ICS). This study aims to assess rates and factors related to low adherence to ICS over time in asthmatic children and adolescents.

METHODS: A concurrent cohort study was carried out for 24 months in 168 randomly selected patients suffering from persistent moderate asthma. All of them were given beclomethasone dipropionate (BDP) free of charge. Adherence rates were verified by pharmacy records (doses filled/doses prescribed). A multivariate analysis evaluated factors related with low adherence rates.

RESULTS: Overall adherence rates were 72.5, 58.6 and 61.1% in the 4th, 12th and 24th months of follow-up, respectively. Factors associated to adherence rates <70% were: mother's schooling level (p = 0.03), replacement of the caregiver (p = 0.03), prescription greater than two puffs/day (p = 0.005), absence of rhinosinusitis (p = 0.002) and age under 7 years (p = 0.04). Only the number of consultations lower than two in a 4-month period was associated to a lower adherence rate in all study periods (p = 0.02).

CONCLUSIONS: Adherence rates decreased over time, even in patients who had received the medication free of charge, and factors related to lower adherence changed during the follow-up. Results have shown that adherence had a dynamic pattern and its determinants should be re-evaluated continuously. Only the number of consultations was associated to a lower adherence rate in all periods, pointing out that health programs must recognize and facilitate the access of patients needing special care, which can contribute for better adherence and reducing asthma morbidity.