Adherence to treatment is key to achieve desired outcomes. In COPD, adherence is generally suboptimal and is impaired by treatment complexity.
To estimate the clinical and economic impact of an improvement in treatment adherence due to an increased use of once-daily single-inhaler triple therapy (SITT) in patients with COPD.
A 7-state Markov model with monthly cycles was developed. Patients with moderate-to-very severe COPD, for whom triple therapy is indicated, were included. Outcomes and costs were estimated and compared for two scenarios: current distribution of adherent patients treated with multiple inhaler triple therapies (MITT) vs a potential scenario where patients shifted to once-daily SITT. In the potential scenario, adherence improvement due to once-daily SITT attributes was estimated. Costing was based on the Spanish National Health System (NHS) perspective (€2019). A 3-year time horizon was defined considering a 3% discount rate for both costs and outcomes.
A target population of 185,111 patients with moderate-to-very severe COPD currently treated with MITT was estimated. A 20% increase in the use of once-daily SITT in the potential scenario raised adherence up to 52%. This resulted in 6835 exacerbations and 532 deaths avoided, with 775 LYs and 594 QALYs gained. Total savings reached €7,082,105. Exacerbation reduction accounted for 61.8% (€4,378,201) of savings.