Epidemiology of patients with asthma in Korea: Analysis of the NHISS database 2006-2015.

Background: There has been a concerning increase in the prevalence and socioeconomic burden of asthma in Korea. Korea's National Health Insurance System (NHIS) covers insurance payment and claims management for all Koreans. Using National Health Insurance Sharing Service (NHISS) claims data. This study aimed to investigate patterns of healthcare utilization and direct cost in patients with asthma over a 10-year period. Methods: In this retrospective population-based study, we examined NHISS claims records between July 2005 and June 2016 and investigated healthcare utilization among patients with asthma based on age group and severity of disease (non-severe asthma [NSA] and severe asthma [SA]). Results: From 2006 to 2015, the total number of patients with asthma in Korea steadily increased from 743 968 to 2 286 309, with a corresponding increase in prevalence from 1.62% to 4.74%. The proportion of patients with SA decreased from 3.16% in 2006 to 1.56% in 2015; the proportion was consistently higher in men than in women. In addition, patients with SA had a higher cost per outpatient visit than patients with NSA, and the number of outpatient visits per year increased. The inhaled corticosteroid (ICS) prescription rate among patients with asthma decreased from 22.9% in 2006 to 15.7% in 2015. Furthermore, for a period of 10 years, more than 40% of patients with SA have been prescribed short-acting ß-2 agonists (SABAs). Conclusions: Although patients with SA comprised a small proportion of patients with asthma, they incurred greater medical costs per person. The pharmaceutical prescription pattern indicated a lack of ICS-based prescriptions and frequent SABA prescriptions.