Treatment patterns and cost of exacerbations in patients with chronic obstructive pulmonary disease using multiple inhaler triple therapy in South Korea

Background: Multiple inhaler triple therapy (MITT), comprising inhaled corticosteroids (ICS), long-acting beta-agonists (LABA), and long-acting muscarinic antagonists (LAMA), has been used as an escalation treatment for patients with chronic obstructive pulmonary disease (COPD). However, real-world use of MITT has not been investigated in Asia, including South Korea. This study reports baseline characteristics of patients with COPD initiated on MITT in South Korea, and their treatment patterns. Healthcare resource utilization (HRU) and costs associated with COPD exacerbations following MITT initiation were also assessed. Methods: This was a retrospective cohort study using the South Korea National Health Insurance database (2014–2018). Included patients were ≥ 40 years, had a COPD diagnosis, were newly initiated on MITT and had ≥ 12 months’ data both before (baseline) and after index date (the first day with overlapping supply of all MITT components). Treatment immediately before initiation and immediately following discontinuation of MITT were identified, and proportion of days covered (PDC) by MITT was calculated. HRU and costs (per person per year [PPPY]) associated with exacerbations were identified following MITT initiation; costs were calculated using the average 2020 exchange rate (0.0008 USD/KRW). Results: Among 37,400 patients, the mean age was 69 (SD 10) years and 73% were males; 56% had ≥ 1 COPD exacerbation during the baseline period, with a mean of 2 (SD 5) events/year. ICS/LABA was the most frequent regimen prescribed immediately before initiation (37%) and immediately following discontinuation (41% of 34,264 patients) of MITT. At 3, 6, and 12 months from treatment initiation, mean PDC was 81%, 63% and 49%, respectively; median treatment duration was 102 days. The mean (95% confidence interval [CI]) number of total visits for severe COPD exacerbations was 0.77 PPPY (0.75–0.78); mean PPPY total healthcare costs were 2093 USD. Conclusions: Patients with COPD in South Korea experienced frequent exacerbations prior to MITT, and PDC by MITT was low. Patients may benefit from early optimization of COPD therapy, and greater emphasis on adherence to inhaled COPD therapy. Severe exacerbations were found to incur substantial costs; treatment alternatives that can reduce the rate of severe exacerbations are likely to minimize healthcare costs.