Assessment of Adherence and Asthma Medication Ratio for a Once-Daily and Twice-Daily Inhaled Corticosteroid/Long-Acting β-Agonist for Asthma.

Background: Although efficacy and safety of fluticasone furoate/vilanterol (FF/VI) and budesonide/formoterol (BUD/F) have been demonstrated in clinical studies, real-world comparisons of utilization have not been performed.

Objective: To compare similar patients with asthma initiating FF/VI or BUD/F on measures of adherence, persistence, and the asthma medication ratio (AMR).

Methods: This was a retrospective cohort study of commercial and Medicare Advantage with Part D enrollees initiating FF/VI or BUD/F for asthma. Adult patients (≥18 years) with at least 15-month (12-month preindex and 3-month postindex) continuous enrollment and 1 or more asthma diagnosis code were eligible for the study. Patients with a history of fixed-dose inhaled corticosteroid/long-acting β-agonist and other respiratory disorders (chronic obstructive pulmonary disease, cystic fibrosis, acute respiratory failure) in the baseline period were excluded. Propensity-score matching was used to balance cohorts on baseline characteristics. Logistic regression and Cox-proportional hazard models were used to assess differences.

Results: A total of 9951 patients met all criteria. After propensity-score matching, 1725 patients were matched in each cohort. Subjects who initiated FF/VI had a significantly higher mean proportion of days covered (P < .001), had 86% greater odds of having a proportion of days covered value of greater than or equal to 0.80 (adjusted odds ratio, 1.86; 95% CI, 1.51-2.30), 26% lower risk of discontinuation (adjusted hazard ratio, 0.74; 95% CI, 0.69-0.79), and 36% greater odds of an AMR of greater than or equal to 0.50 (adjusted odds ratio, 1.36; 95% CI, 1.23-1.50) compared with BUD/F.

Conclusions: Adherence and treatment persistence were low in both cohorts; however, patients initiating once-daily FF/VI were more likely to be adherent, have an AMR of greater than or equal to 0.5, and were less likely to discontinue therapy compared with patients initiating twice-daily BUD/F (GlaxoSmithKline Study HO1617302/206482).