Treatment persistence and exacerbations in patients with asthma initiating treatment with inhaled corticosteroids and beta-adrenergic agonists: retrospective cohort study

OBJECTIVE: To determine treatment persistence and exacerbations in patients initiating inhaler treatment with fixed-dose combinations of inhaled corticosteroids/long-acting beta-2-adrenergic agonists (ICS/LABA) for the treatment of asthma. DESIGN: Retrospective observational study conducted by review of electronic medical records (database: Fundación RediSS). SETTING: Retrospective cohort study. The follow-up period was 1 year. PARTICIPANTS: The study included patients aged ≥18 years who started treatment with ICS/LABA and met the inclusion/exclusion criteria. MAIN OUTCOMES AND MEASURES: The study groups were fluticasone propionate/salmeterol (FP/SAL), beclomethasone/formoterol (BDP/FORM), budesonide/formoterol (BUD/FORM), fluticasone furoate/vilanterol (FF/VI) and fluticasone propionate/formoterol (FP/FORM). The main measurements were persistence, medication possession ratio (MPR) and exacerbations. Statistical significance was established as p<0.05. RESULTS: In total, 3203 patients were recruited for the study. By groups, 31.1% FP/SAL, 28.6% BDP/FORM, 25.0% BUD/FORM, 8.2% FF/VI and 7.0% FP/FORM. The mean age was 52.2 years, 60.8% were female and 44.9% had persistent-moderate asthma. Treatment persistence was 61.7% (95% CI 60.0% to 63.4%) and by study group it was FP/SAL: 60.7%, BDP/FORM: 61.2%, BUD/FORM: 60.3%, FF/VI: 66.7% and FP/FORM: 67.6% (p=0.046). MPR by study group was FP/SAL: 74.3%, BDP/FORM: 73.8%, BUD/FORM: 74.6%, FF/VI: 79.4% and FP/FORM: 80.6% (p=0.028). The mortality rate was 2.9%. By treatment group, exacerbations were FP/SAL: 21.9% (95% CI 19.3% to 24.5%), BDP/FORM: 22.2% (95% CI 19.5% to 24.9%), BUD/FORM: 22.8% (95% CI 19.9% to 25.7%), FF/VI: 17.9% (95% CI 14.9% to 20.7%) and FP/FORM: 16.0% (95% CI 12.2% to 19.3%), p=0.036. CONCLUSIONS: Patients undergoing treatment with FP/FORM and FF/VI versus FP/SAL, BDP/FORM and BUD/FORM were associated with greater treatment adherence (persistence, MPR) and lower rates of exacerbations. However, further studies will be needed to strengthen the consistency of the results.