RESUMO
BACKGROUND: Sixty-five percent of people with severe asthma and a fractional exhaled nitric oxide (Feno) greater than or equal to 45 parts per billion (ppb) are nonadherent to inhaled corticosteroids (ICSs). Digital devices recording both time of use and inhaler technique identify nonadherence and ICS responsiveness but are not widely available. As the NEXThaler dose counter activates only at an inspiratory flow rate of 35 L/min, this may provide an alternative to identifying ICS responsiveness. OBJECTIVE: To assess ICS adherence and responsiveness in severe asthma using beclometasone/formoterol (200/6 µg) NEXThaler (BFN) dose-counting. METHODS: Patients with severe asthma with a Feno greater than or equal to 45 ppb were invited to use BFN in place of their usual ICS/long-acting ß2-agonist. Feno, 6-item Asthma Control Questionnaire score, lung function, and blood eosinophil count were monitored for 3 months. A log10ΔFeno of greater than or equal to 0.24 was used to define Feno suppression as the primary marker of ICS responsiveness at day 28. RESULTS: Twenty-seven of 48 (56%) patients demonstrated significant Feno suppression at month 1 (median pre-114, post-48 ppb, P < .001). A small but significant reduction occurred in Feno nonsuppressors. The 6-item Asthma Control Questionnaire score fell a median 1.2 units in Feno suppressors (P < .001) and 0.5 units in nonsuppressors (P = .025). These effects were sustained until month 3 in Feno suppressors, with a significant improvement in FEV1 and blood eosinophils. Sixty-seven percent (18 of 27) of those with baseline ICS/long-acting ß2-agonist prescription refills of 80% or more were Feno suppressors, suggesting prior nonadherence despite adequate prescription collection. Seventy-nine percent of Feno suppressors did not require biologics within mean 11.4 months from initial dose counting. CONCLUSIONS: BFN dose-counting identifies ICS responsiveness in severe asthma with the implication that these patients may not need to progress to biological therapies.
