Title: Comparing The Risk of Asthma Exacerbation Between Use of Inhaled Corticosteroids and Leukotriene Receptor Antagonists in The Elderly Patients With Asthma
Abstract: There are few treatment guidelines on the elderly asthma patients since they have been excluded from randomized control trials. The elderly often prefer oral medications to inhalants, which are the cornerstones of asthma, because of familiarity and ease of use. This research aimed to compare the risk of asthma exacerbation between use of inhaled corticosteroids (ICSs) and leukotriene receptor antagonists (LTRAs) in elderly asthma patients in real-world. We extracted elderly patients newly diagnosed with asthma corresponding step 2 based on guideline from January 1, 2009 to December 31, 2013 using National Sample Cohort data of Korea. The patients on step 2 were identified by having at least 2 claims with diagnosis of asthma and prescription of ICSs only or LTRAs only. We defined the date of first prescription for each medication as index date. We identified the asthma-related healthcare utilization and medications in two groups for 1-year. And we compared the risk of asthma exacerbation between two groups by calculating the time to first asthma exacerbation. The statistical analysis was performed by using chi-square test and Cox proportional-hazard model. The matched number of patients who used ICSs and LTRAs for the first treatment was 373 and 409, respectively. Adjusted hazard ratio of asthma exacerbation in LTRAs group verses ICSs were not statistically significant. During the 1-year follow-up, the proportion of switching from ICSs to LTRAs was 14.8%, meanwhile, the opposite was 2.0%. The proportion of patients who used the symptom controller in ICSs group and LTRAs group was 47.2% and 7.6%, respectively (p<0.0001). LTRAs showed no difference from ICSs in the risk of asthma exacerbation in the elderly. Furthermore, based on the large number of patients who switched the medication from ICSs to LTRAs, it could be considered to use LTRAs as the first-line treatment for the elderly asthma patients.