Abstract Objective: To determine the rate of adherence to treatment with inhaled corticosteroids in patients with severe asthma, to identify predictive factors for adherence and to evaluate the relationship between adherence to treatment and parameters of clinical and functional response. Methods: Prospective cohort study of patients enrolled in the Program for the Control of Asthma and Allergic Rhinitis in the state of Bahia, Brazil. The study comprised 160 patients with severe asthma, monitored for 180 days in order to evaluate adherence (dependent variable) to the prescribed inhaled corticosteroid. Independent variables were assessed at baseline and for a six-month follow-up period by means of interviews and the completion of a standardized questionnaire. Patients recorded the missed doses in a diary. Results: Of the 160 patients, 158 completed the study. Adherence rate was 83.8%. Of the 158 patients, 112 (70.9%) were considered adherent (cut-off point: 80% of prescribed doses administered). There was a significant association between asthma control and adherence to treatment. Predictors of poor adherence were adverse effects, living far from the referral center, limited resources to pay for transportation and dose schedule. Other factors, such as depressive symptoms, religion and economic status, were not associated with poor adherence. Conclusions: Adherence to asthma treatment was high and was associated with the clinical response to treatment, in a sample of patients with severe asthma enrolled in a public program that provides free medication and the assistance of a multiprofessional specialized team in a referral center.

Keywords: Asthma; Directly observed therapy; Treatment outcome; Patient compliance; Pharmacy.