Real-world digital smart inhaler (DSI) monitoring in children with uncontrolled Asthma

Introduction: Asthma preventer medication adherence in children is often poor leading to uncontrolled asthma (Engelkes 2015). A previous randomised trial showed adherence monitoring using DSI reduces asthma attacks (Morton Thorax 2017). Less data exists on reductions in rescue inhaler use. Implementation issues are poorly reported and should be addressed before DSI can be widely adopted.

Aim: To evaluate the clinical utility of DSI in a real-world clinical setting.

Methods: Prospective observational cohort study using DSI and digital health platform (Propeller Health) in a specialist paediatric asthma clinic. Between Oct-2021 and Dec-2022, consecutive children with uncontrolled asthma were enrolled. DSI sensors, connected to a smartphone app, recorded preventer and rescue inhalers usage, which were remotely reviewed monthly for 6 months. FeNO and spirometry was measured before and pragmatically during the monitoring period.

Results: 51 users were enrolled. 95% of users in month 1 (M1) and 69% in month 6 (M6) had ≥75% preventer adherence. Mean reliever usage was 72 puffs in M1 and 41 puffs at M6. 8% of users had ≤2 daytime reliever use/week and no night use in M1, compared to 30% at M6. Mean FEV1/FVC z-score was -2.36 at baseline to -1.07 (P=0.011) towards the end of monitoring. Mean FeNO levels were unchanged. 4 users returned devices and some children had periods of inactivity for various reasons.

Conclusion: DSI are a useful addition to specialist paediatric asthma services and acceptable to most families. Observed improvements in lung function supports clinical utility of DSI. Yet, changes to asthma service delivery are needed to improve their effectiveness and overcome implementation challenges.