Clinical Outcomes in People with Difficult-to-Control Asthma Using Electronic Monitoring to Support Medication Adherence

Background: Nonadherence in difficult-to-control asthma can be identified using 7-day FeNO suppression testing where patients take additional fluticasone via Diskus with an Inhaler Compliance Assessment (INCA) acoustic monitoring device attached, and self-measure FeNO at home. However, this is inconvenient for patients attending a tertiary center and limited by FeNO meter availability. It is not known if this approach alters clinical outcomes.

Objectives: To examine patient acceptability and the effectiveness of replacing usual combination inhaled corticosteroid (ICS)/long-acting β₂-agonist (LABA) therapy with a fluticasone/salmeterol Diskus 500+INCA for 28 days as the initial intervention, compared with the 7-day FeNO suppression test, and to explore clinical outcomes after INCA monitoring.

Methods: A service evaluation of FeNO suppression testing was undertaken in clinical practice.

Results: Twenty-one of 23 subjects offered replacement of their usual ICS/LABA with fluticasone/salmeterol+INCA as the initial intervention accepted and completed 28 days of monitoring. Fourteen (66.6%) patients reduced their FeNO by >42% (FeNO suppressors), accompanied by improvements in forced expiratory volume in 1 second, Asthma Control Questionnaire, and blood eosinophils, similar to the 7-day test (n = 74). Twenty-two of 62 (35.5%) FeNO suppressors progressed to biological therapy, compared with 24 of 33 (72.7%) nonsuppressors (P = .0006). FeNO suppressors taking maintenance prednisolone (n = 13) who did not receive biological therapy reduced the median baseline dose from 10 to 3 mg, with further reductions limited by adrenal suppression.

Conclusion: Replacing existing inhaled therapy with fluticasone/salmeterol+INCA for 28 days is acceptable to the majority of people with difficult-to-control asthma and identifies prior medication nonadherence. INCA monitoring coupled with clinical support potentially improves patient adherence and asthma control, preventing unnecessary progression to biological therapy.