Real-world Treatment Patterns, Outcomes, and Healthcare Resource Utilization in Newly Treated Korean Patients With Asthma: A Retrospective Cohort Study

Purpose: Although asthma treatment guidelines recommend regular inhaled medication, real-world treatment patterns and outcomes in South Korea have not been examined. We examined real-world treatment patterns and outcomes among patients treated for asthma in South Korea. Methods: This retrospective cohort study utilized data from the South Korean National Health Insurance database (2013-2016). Newly treated patients with asthma aged ≥18 years without history of chronic obstructive pulmonary disease were included. Initial and maintenance medication prescriptions were examined. Treatment discontinuation and switch were described. Asthma exacerbation rates, poor asthma control, and healthcare resource utilization (HRU) were compared between maintenance treatment groups (inhaled versus oral) using adjusted incidence rate ratios (aIRR) and hazard ratios (aHR). Results: Overall, 1,054,707 patients initiated any asthma medication; 37,868 patients initiated inhaled (n = 9,983, 26.4%) or oral (n = 27,885, 73.6%) maintenance medication. More patients initiating inhaled versus oral asthma medication discontinued treatment within 12 months (94.4% vs. 86.3%; P < 0.0001). Patients treated with inhaled and oral medication switched treatment (2.5% and 2.3%; P = 0.4160, respectively). Patients initiating inhaled medication had significantly lower rates of asthma exacerbation (aIRR, 0.52; 95% CI, 0.39-0.69), lack of asthma control (aHR, 0.55; 95% CI, 0.48-0.62; P < 0.0001), all-cause and asthma-related HRU versus oral medication. Conclusions: Despite current asthma guidelines, more patients in South Korea were prescribed oral than inhaled medications, resulting in suboptimal asthma management and increased HRU. This study highlights the need to reduce oral corticosteroid prescriptions for optimized treatment in asthma management.