Smart Inhaler Feedback In Children With Uncontrolled Asthma

Key Takeaways

• Several asthma control measures improved over time, but no significant between-group difference was observed.
• The intervention compared Respiro app-based reminders and personalized inhalation feedback with monitoring without feedback in children aged 6 to 18 years.
• Inhalation technique and therapy adherence also did not differ significantly over time between groups.

A smart inhaler feedback strategy did not produce a measurable between-group advantage by the end of the randomized phase in children with uncontrolled asthma. At phase 2 completion, 87% (13/15) of controls and 78% (10/13) of intervention participants met at least one predefined clinical improvement criterion, with no significant difference. The IMAGINE randomized controlled trial enrolled children with uncontrolled moderate to severe asthma and compared monitored feedback with monitoring alone. Asthma control measures also did not separate over time during the randomized comparison.

IMAGINE included a 4-week observational run-in, a 6-week randomized phase, and a 6-week observational follow-up. Researchers enrolled and randomized 34 children aged 6 to 18 years with uncontrolled moderate to severe asthma from October 2019 through October 2023 at a large teaching hospital in the Netherlands. The intervention group received Respiro app-based reminders plus personalized inhalation feedback, while controls were monitored without feedback. Allocation was 1:1 with blocking and stratification by age and nasal corticosteroid use, and blinding was not possible. Main asthma control measures were predFEV1, lung function reversibility, lung function variability, ACT, and C-ACT across study visits.

By the end of phase 2, both groups had improved in several clinical parameters, but between-group trajectories did not differ significantly over time. Overall clinical improvement was not significantly different (P=.52), and the between-group comparison for absolute C-ACT change was also nonsignificant (P=.57). Comparisons for reversibility and lung function variability were likewise null, with P=.71 and P=.84, respectively. Inhalation technique and therapy adherence also remained similar over time, with P=.70 and P=.14. During the randomized phase, monitored feedback was not associated with superior asthma control, adherence, or inhalation technique compared with monitoring alone.

The Respiro add-on device recorded vibration-pattern data during home use that included peak inspiratory flow, inhalation duration, dosing intervals, and device orientation. Investigators also defined clinical improvement through predefined thresholds tied to FEV1, C-ACT, reversibility, and lung function variability. The trial stopped early for futility after an interim analysis, and suboptimal adherence to home measurements may have influenced interpretation of lung function variability. Some participants in the feedback group disabled auditory warning signals during the study, although frequency data were unavailable, and the authors noted reduced statistical power and limited generalizability. Overall, objective monitoring in both groups was accompanied by within-group improvement over time, while immediate feedback was not linked to superior between-group outcomes.