A Comparison of the Effectiveness of Asthma Medications on Asthma Exacerbations in Real World National Cohort

Background: Although a wide variety of asthma medications have been developed and are used in clinical practice, there is limited evidence of their comparative effects on asthma exacerbations. Methods: We used claims data provided by the Health Insurance Review and Assessment Service. We selected subjects commencing asthma treatment between July 1, 2017 and June 30, 2018, with no change in drug regimen. The primary outcome was asthma exacerbation requiring systemic corticosteroids. Cox regression analysis was used to assess outcomes considering the exacerbation-free period. Results: Of the 254,951 asthma subjects, 107,694 subjects (42.2%) experienced asthma exacerbation. Inhaled corticosteroids (ICSs) (hazard ratio [HR], 0.378–0.508), ICS-long-acting β₂-agonist (LABAs) (HR, 0.284–0.479), long-acting muscarine antagonists (LAMAs) (HR, 0.432–0.572), leukotriene receptor antagonists (LTRAs) (HR, 0.371–0.419), and xanthines (HR, 0.326–0.482) significantly reduced the rate of first and second exacerbation of asthma (all P-values, <0.001). The clinical effectiveness of asthma medications varied according to the active ingredient (HR 0.164–0.670) and was significant for all active ingredients (all P-values, <0.001). The effectiveness of combination treatment using ICS-LABA and LTRA varied (HR, 0.159–0.670); however, all combination treatment options evaluated were effective in preventing asthma exacerbations (all P-values, <0.001). Long-term use of ICS-LABA (HR, 0.278–0.653), LTRA (HR, 0.259–0.628), and xanthines (HR, 0.351–0.783) showed consistent effectiveness (all P-values, <0.001). Conclusion: This real-world study showed that the effectiveness of asthma medications varied according to drug type, active ingredient, combination, and period of use, although effectiveness was significant in all cases studied.