Cost-effectiveness of tiotropium in elderly patients with severe asthma using real-world data.

Abstract Background Tiotropium has the potential to alleviate asthmatic symptoms caused by the aging of lungs. However, few studies have focused on specific treatments for elderly asthma patients. Objectives This study aimed to estimate the cost-effectiveness of adding tiotropium to inhaled corticosteroids and long-acting beta-agonists (ICS/LABA) in elderly severe asthma patients using real-world data. Methods Phase I was a retrospective cohort study using the National Health Insurance claims data to measure clinical and economic outcomes. In phase Ⅱ, a Markov model was constructed to evaluate cost-effectiveness from Korean healthcare system perspective, based on phase I, including two health states and an asthma exacerbation event. We estimated cost given in 2018 US dollars, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Subgroup analyses for poorly controlled asthma patients (frequent short-acting beta-agonist (SABA) users; frequent exacerbators) were performed. Results In elderly severe asthma patients, the incremental cost and effectiveness in the tiotropium group compared to the ICS/LABA group were $2,281 and 0.038 QALYs, respectively. The ICER was $60,074/QALY, indicating that the addition of tiotropium is not a cost-effective alternative. Meanwhile, two subgroups with poorly controlled asthma showed that adding tiotropium is a cost-effective alternative (frequent SABA users $4,078/QALY; frequent exacerbators $8,332/QALY). Conclusion Tiotropium shows a higher cost-effectiveness profile when applied to elderly patients with uncontrolled symptoms. These results using real-world evidence provide information beyond the clinical outcomes reported by randomized clinical trials, providing a complementary ground in establishing the reimbursement criteria of tiotropium for elderly patients with severe asthma.