Background: Digital inhalers provide real-time feedback on inhaler usage and have shown to increase medication adherence and inform step-up treatment decisions. Yet, no model exists to evaluate the cost-effectiveness of digital inhalers.

Aims and objectives: To develop a cost-effectiveness model to assess the value of digital medication adherence enhancing strategies in patients with asthma, to validate the model and to apply the model to assess the cost-effectiveness of digital inhalers.

Methods: A new Markov model was developed. The model structure was determined by biological and clinical understanding of asthma and was further informed by expert consultation. Internal and external validation was performed according to the AdViSHE tool. The INCA Sun study data set was applied to evaluate cost-effectiveness of digital inhalers.

Results: A cost-effectiveness analysis of the INCA Sun study from a societal perspective showed per-patient costs for digital inhalers and usual care of ?7,546 and ?10,752, respectively, over a 1-year time horizon, and ?181,438 and ?184,645, respectively, over a lifetime horizon, reflecting a cost saving of ?3,207 for digital inhalers. Add-on biologic therapies accounted for 69% of the total costs in the usual care group and for 49% in the digital inhaler group in the first year.

Conclusions: The developed model can predict the cost-effectiveness of digital medication adherence enhancing strategies in asthma. Furthermore, we found that the digital inhaler intervention used in the INCA Sun trial is cost-saving, by optimizing medication adherence and inhaler technique and avoiding biologic therapy prescriptions.