Exacerbations and Their Outcomes International (EXACOS International): Burden of Severe Exacerbations of COPD and the Association Between Frequency of Severe Exacerbations and Clinical and Health-care Utilization Outcomes

1. BACKGROUND AND RATIONALE Chronic obstructive pulmonary disease (COPD) is a common, progressive disease characterized by airflow obstruction which is not fully reversible. Acute exacerbations of COPD (AECOPD) are worsening of COPD symptoms (breathlessness, cough, and sputum volume and purulence) beyond normal day to day variation. Between 30-50% of patients with COPD experience at least one AECOPD per year [1]. Even a single moderate AECOPD increases risk of future multiple AECOPD events, starting a spiral of excessive disease progression and leading to an increased risk of death [2]. AECOPDs have also been associated with other clinical outcomes such as accelerated lung function decline [3,4].

Studies have shown that AECOPDs are related to future AECOPDs, however, little is known about clinical burden and health care utilization in the COPD population [2, 5]. To date, most of published literature reports a combined category of moderate-severe exacerbations, typically stratifying patients as experiencing frequent (i.e. two or more events per patient-year) vs. infrequent (none or one) exacerbations.

The aim of this study is to quantify the burden of severe AECOPD in South Korea, by investigating the association between frequency of severe AECOPD and clinical and health-care utilization outcomes.

This study will help to understand the relationship between severe AECOPD and clinical and health care utilization burden in South Korea with no established health care databases. 2. OBJECTIVES AND HYPOTHESES The objective is to quantify the burden of severe AECOPD by describing the clinical and health care utilization burden of AECOPD by frequency.

2.1 Primary Objectives