Estimation of the Clinical and Economic Impact of an Improvement in Adherence Based on the Use of Once-Daily Single-Inhaler Triple Therapy in Patients with COPD

BACKGROUND: Adherence to treatment is key to achieve desired outcomes. In COPD, adherence is generally suboptimal and is impaired by treatment complexity. OBJECTIVE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: Increasing the use of once-daily SITT in patients with moderate-to-very severe COPD treated with triple therapy would be associated with an improvement in adherence, a reduction of exacerbations and deaths, and cost savings for the Spanish NHS.