The trend of Medication use and Mortality in chronic obstructive pulmonary disease in Korea: A nationwide cohort study 2002-2013

Introduction: Chronic obstructive pulmonary disease(COPD) is the leading cause of death worldwide. There are no population-based cohort studies about the trend of COPD medication in Korea. Therefore, we analyzed the change in treatment patterns in the use of oral and inhalation drugs. Methods: We used National Health Insurance Service-National Sample Cohort (NHIS-NSC), a large, population-based representative cohort. COPD patients are identified using the International Classification of Disease-Tenth Revision (ICD-10) and prescription details from 2003 to 2013. We analyzed temporal trends in the treatment of COPD, and mortality was compared between the group using only oral drugs and the group using inhalation agents. Results: Among the cohort, 11,360 people who were above 40 years old were newly diagnosed with COPD. From 2003 to 2013, the prescription frequency of oral drug has been decreased gradually. The percentage of patients who were prescribed inhalation medication increased from 4.5% to 55.8%. Among these patients, 4,973 patients used oral drugs alone, and 6,338 patients were treated with inhalation drugs. Among them, a total of 2,406 are dead during the 10-year follow-up period. The 5-year mortality of COPD patients was 16.4%. Mortality is not different according to medication after adjusting sex, age, and comorbidities by multivariate cox regression analysis. Conclusions: This study is the first cohort study analyzing the medication and mortality in COPD patients. We demonstrate a decrease in the use of oral drugs and an increase in the prescription of inhalation agents. But inhalation use is irregular, so we could not demonstrate a mortality difference.