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.