OBJECTIVES : To estimate proportion of exacerbation leading to hospitalization or intensive care unit (ICU) admission in patients with severe and uncontrolled asthma in Korea

METHODS : This study was performed using nationally representative data, Health Insurance Review and Assessment Service-National Patient Sample 2016, that included medical and pharmacy claims of approximately 1.4 million patients. To define patients and exacerbation, we used the recommendation of European Respiratory Society/American Thoracic Society and Global Initiative for Asthma guideline. We included patients with severe and uncontrolled asthma defined as subjects satisfying all conditions as follows: (1) ≥1 claim of asthma diagnosis (ICD-10 code J45/J46); (2) ≥1 claim of inhaled corticosteroid [ICS]); (3) ≥1 claim of additional controller or ≥180 days use of add-on low dose oral corticosteroids (OCS); and (4) ≥2 exacerbations or ≥1 exacerbation leading to hospitalization or ICU admission. Additional controller included LABA, leukotriene modifiers, theophylline, and tiotropium. Low dose OCS was defined as ≤7.5 mg/day prednisolone (or equivalent). Exacerbation was defined as outpatient visit, emergency department visit, hospitalization, or ICU admission with asthma diagnosis with corticosteroids bursts (defined as >30 mg/day prednisolone for >3 days or 200 mg hydrocortisone injection). Proportion of exacerbation leading to hospitalization or ICU admission was estimated as dividing the number of exacerbation episode with hospitalization or ICU admission by the number of exacerbation episode in patients with severe and uncontrolled asthma.

RESULTS : Among eighty patients (with 138 exacerbation episodes) with severe and uncontrolled asthma, the mean age was 57.65 years, and 53.75% were women. The proportion of exacerbation leading to hospitalization or ICU admission was 53.62%. Of the exacerbations leading to hospitalization or ICU admission, the proportion of exacerbation leading to ICU admission was 13.51%.

CONCLUSIONS : Among patients with severe and uncontrolled asthma, the occurrence of exacerbation requiring hospitalization or ICU admission was relatively high. Effective management strategy is needed.