Data from chronic obstructive pulmonary disease patients awaiting lung transplantation which performed a pulmonary rehabilitation program will be analyzed retrospectively. Acute exacerbations occur frequently in these patients and have a major impact on the course of the disease. This study investigates the prevalence and the impact of acute exacerbations during pulmonary Rehabilitation in patients with severe chronic obstructive pulmonary disease patients awaiting lung Transplantation that continued the Rehabilitation program despite an acute exacerbation. Data will be taken from the internal database of the reference center (Schoen Klinik Berchtesgadener Land, Schoenau, Germany) where these data were collected during clinical routine.

Inclusion Criteria:

• confirmed diagnosis of chronic obstructive pulmonary disease including patients with alpha-1 antitrypsin deficiency
• listed for lung Transplantation or in the Evaluation process for lung transplantation
• performed a pulmonary rehabilitation program at the reference center

Exclusion Criteria:

• patients that discontinued the pulmonary Rehabilitation program due to any reason and could therefore not perform assessement tests at the end of regular Rehabilitation program

data will be collected from the internal database of the reference Center