Chronic obstructive pulmonary disease is a chronic inflammatory lung disease that causes obstructed airflow from the lung, characterized by chronic cough, dyspnea, and sputum production, which often misunderstood as aging or catching a cold. These symptoms may be progressive over time. To provide better disease management and early detecting, pulmonary rehabilitation is now considered a fundamental component of the integrated disease management of this population. However, few studies have evaluated the beneficial outcomes in patients referred to pulmonary rehabilitation. Therefore, the purpose of this study is to investigate the clinical outcomes in patients referred to pulmonary rehabilitation in National Taiwan University Hospital.

Inclusion criteria:

1. age > 20 years old
2. patients with chronic respiratory disease diagnosed by physician that referred to pulmonary rehabilitation in National Taiwan University Hospital including, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, bronchiectasis
3. can cooperate with pulmonary rehabilitation clinic

Exclusion criteria:

1. angina, acute myocardial infarction in the previous one month
2. pregnancy

Patients with chronic respiratory disease: chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, bronchiectasis.