Global burden of medication non-adherence in chronic obstructive pulmonary disease (COPD) and asthma: a narrative review of the clinical and economic case for smart inhalers

Medication non-adherence to asthma and chronic obstructive pulmonary disease therapy poses a significant burden for patients and societies. Non-adherence encompasses poor initiation, implementation (including poor inhalation technique) and non-persistence. Globally, non-adherence is associated with poor clinical outcomes, reduced quality of life and high healthcare and societal costs. Costs are mainly caused by excess hospitalizations and impaired work productivity. Multiple intervention programs to increase adherence in patients with asthma and chronic obstructive pulmonary disease have been conducted. However, these intervention programs are generally not as effective as intended. Additionally, adherence outcomes are mostly examined with non-objective or non-granular measures (e.g., self-report, dose count, pharmacy records). Recently developed smart inhalers could be the key to objectively diagnose and manage non-adherence effectively in patients with asthma and chronic obstructive pulmonary disease. Smart inhalers register usage of the inhaler, record time and date, send reminders, give feedback about adherence and some are able to assess inhaler technique and predict exacerbations. Still, some limitations need to be overcome before smart inhalers can be incorporated in usual care. For example, their cost-effectiveness and budget impact need to be examined. It is likely that smart inhalers are particularly cost-effective in specific asthma and chronic obstructive pulmonary disease subgroups, including patients with asthma eligible for additional GINA-5 therapy (oral corticosteroids or biologics), patients with severe asthma in GINA-5, patients with asthma with short-acting beta2 agonists overuse, patients with asthma and chronic obstructive pulmonary disease with frequent exacerbations and patients with asthma and chronic obstructive pulmonary disease of working-age. While there is high potential and evidence is accumulating, a final push seems needed to cost-effectively integrate smart inhalers in the daily management of patients with asthma and chronic obstructive pulmonary disease.