1. Does pulmonary rehabilitation (PR) reduce mortality risk?
2. Does PR in the post-hospitalization period reduce subsequent health care utilization?
3. Can the principles of PR be applied more broadly across the disease spectrum to reduce morbidity, mortality, and health care expenditures in patients with COPD?
4. Does early PR following hospitalization for acute exacerbation reduce mortality and readmission rates for patients with COPD?
5. Does PR improve sleep in patients with COPD (and other chronic lung diseases)?
6. What is the comparative effectiveness of short-term vs. chronic (indefinite) PR on patient-reported outcomes (symptom frequency, activities of daily living, quality of life, sleep quality, exacerbations)?