Adherence with montelukast or fluticasone in a long-term clinical trial: Results from the Mild Asthma Montelukast Versus Inhaled Corticosteroid Trial

Background: Nonadherence with asthma therapy is common and may contribute to poor clinical outcomes. Objective: To examine the effect of dosing frequency and mode of delivery of therapy on adherence and clinical outcomes. Methods: We examined adherence in patients with mild persistent asthma (15-85 years) enrolled in a randomized study of montelukast (10 mg once daily) or fluticasone (88 μg, 2 puffs twice daily) during a 12-week double-blind treatment period (DB), followed by a 36-week open-label trial (OL). Adherence was monitored using eDEM for montelukast/placebo and MDILog devices for fluticasone/placebo. Results: Participants used at least 1 puff of inhaled therapy on 83.3% DB/76.8% OL of days and at least 1 dose of oral therapy on 77.5%/71.4% of days (P < .0001). Subjects used inhaled therapy less than prescribed on 49.5%/57.5% of days, compared with 22.5%/28.6% of days for oral therapy (P < .0001). In the DB, a dose-response relationship was observed with fluticasone and asthma rescue-free days (P = .02) and FEV₁ percent predicted (P < .01) only for patients with FEV₁ ≤ 86%. In the OL period, a dose-response relationship was observed with fluticasone and FEV₁ percent predicted (P < .001). Conclusion: Whereas subjects were more likely to use inhaled fluticasone/placebo at least once a day, subjects were more likely to take once-daily oral montelukast/placebo as prescribed. Clinical outcomes were inconsistently associated with adherence levels. Clinical implications: Patients were less likely to be fully adherent with twice-daily therapy than with once-daily therapy, but most still achieved adequate asthma control.