Long-Term Effectiveness of a Digital Inhaler on Medication Adherence and Clinical Outcomes in Adult Asthma Patients in Primary Care: The Cluster Randomized Controlled ACCEPTANCE Trial.

Background: Digital inhalers can support medication adherence and asthma control in the short-term. Yet, long-term benefits are unknown.

Objective: To investigate the clinical effects, usability, and cost-effectiveness of a digital inhaler.

Methods: This was an open-label cluster randomized controlled trial of 12 months in Dutch primary care. Adults with suboptimal controlled asthma and nonadherence were eligible. General practices were randomly allocated to either intervention or control, stratified by practice size. Intervention and control patients received an electronic monitoring device attached to their budesonide/formoterol SYMBICORT Turbuhaler maintenance inhaler. Intervention patients used a smartphone application for data insights and reminders. Control patients' inhaler use was passively monitored. Primary outcome was 1-year medication adherence. Secondary outcomes included asthma control, quality of life, usability, and cost-effectiveness.

Results: Between June 27, 2019 and September 30, 2022, 136 clusters containing 164 participants were randomized (82 participants across 68 clusters in both groups). Estimated marginal means (EMM) for medication adherence were 71.4% (95% CI, 67.1-75.4) and 59.9% (95% CI, 55.0-64.7) in the intervention and control groups, respectively. Medication adherence was higher in the intervention group at week 2 (odds ratio [OR] = 2.19; 95% CI, 1.63-2.95). The difference in medication adherence between groups declined over time (P < .0001); no significant difference was found at study end (OR = 1.23; 95% CI, 0.91-1.66). Overall, Asthma Control Questionnaire-5 scores were significantly better (P = .0056) in the intervention group (EMM, 1.31; 95% CI, 1.18-1.44) compared with control (EMM, 1.56; 95% CI, 1.44-1.68). Quality of life (Mini Asthma Quality of Life Questionnaire scores) did not differ significantly between groups (P = .0530). However, the intervention group was almost three times more likely to reach the minimal clinically important difference for asthma-related quality of life (OR = 2.73; 95% CI, 1.02-7.54). Mean system usability score was 80.1 (SD, 13.8). Cost per 0.5-point Asthma Control Questionnaire-5 decrease was €278.

Conclusion: Use of this digital inhaler led to significant improvements in medication adherence in the short term and to sustained improved asthma control over 12 months.