Cost-Effectiveness of Tiotropium in Elderly Patients with Severe Asthma Using Real-World Data.

Abstract

Tiotropium has the potential to alleviate asthmatic symptoms caused by the aging of lungs. However, few studies have focused on specific treatments for elderly patients with asthma. To estimate the cost-effectiveness of adding tiotropium to inhaled corticosteroids and long-acting beta-agonists in elderly patients with severe asthma using real-world data. 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 health care system perspective, based on phase I, including 2 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. Subgroup analyses for patients with poorly controlled symptoms (frequent short-acting beta-agonist users; frequent exacerbators) were performed. In elderly patients with severe asthma, the incremental cost and effectiveness in the tiotropium group compared with the inhaled corticosteroid and long-acting beta-agonist group were $2281 and 0.038 QALYs, respectively. The incremental cost-effectiveness ratio was $60,074/QALY, indicating that the addition of tiotropium is not a cost-effective alternative. Meanwhile, 2 subgroups with poorly controlled symptoms showed that adding tiotropium is a cost-effective alternative (frequent short-acting beta-agonist users $4078/QALY; frequent exacerbators $8332/QALY). 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 controlled trials, providing a complementary ground in establishing the reimbursement criteria of tiotropium for elderly patients with severe asthma.