Inclusion and exclusion criteria

Inclusion criteria
  • Diagnosis of COPD: smoking history >10 pack-years, post-bronchodilator FEV1/FVC <0.7 and FEV1 <80% predicted (post-bronchodilator)

  • Increased symptoms: cough, sputum volume or purulence, breathlessness

  • Age >35 years

Exclusion criteria
  • New chest radiographic infiltrate consistent with pneumonia

  • Other causes of breathlessness; heart failure, pulmonary embolism, etc.

  • Asthma

  • Inability to provide informed consent

FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity.