Approximately 60 to 70% of people with COPD have chronic cough and phlegm, the cardinal symptoms of chronic bronchitis or chronic mucus hypersecretion (CMH). Once thought to be a relatively benign condition, recent evidence shows that CMH in patients with established COPD is associated with greater decline in lung function, more frequent respiratory infections, more frequent exacerbations and increased mortality.Using mechanical airway clearance techniques (The Vest) will diminish exacerbations of COPD which will improve respiratory health status.
Comparison: Patients randomly assigned to the vest will have fewer exacerbations of COPD,better quality of life and less health care use compared to patients assigned to a sham vest.