Adherence to Treatment in Severe Asthma: Predicting Factors in a Program for Asthma Control in Brazil

BACKGROUND: In Brazil, like many other low- to middle-income countries, most asthmatic patients cannot afford the medication necessary to prevent exacerbations. The reference clinic of the Programme for Asthma Control in Bahia (ProAR; Salvador-Bahia) offers free medical care, pharmaceutical assistance (inhaled medication) and patient education. The reference clinic is accessible to all the population of Salvador and the Programme is targeted on severe asthma. OBJECTIVE: The aim of the present study was to evaluate adherence to inhaled medication in severe asthmatics enrolled in ProAR. METHODS: A sub-group of 160 consecutive severe asthmatics enrolled in ProAR were followed prospectively for 6 months. All patients were assessed by means the Asthma Control Questionnaire, the Beck Depression Inventory and spirometry. The rate of adherence to inhaled corticosteroid was checked monthly. A cut-off point of 80% of the doses prescribed in the period was used to define patients as adherent. RESULTS: Of the one hundred-sixty patients with severe asthma included, it was possible to objectively assess adherence to the use of the inhaled corticosteroid in 158. Among these, 112 (70.9%) were considered adherent according to the adopted cut-off point. The rate of adherence in the whole sample of subjects was 83.9% of the prescribed doses. 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. CONCLUSION: In the present study, adherence to treatment was high. In a sample of patients with severe asthma managed in a public program that provides free medication and multidisciplinary treatment at a referral center, adherence to treatment was found to be associated with favorable clinical outcomes.