Criteria for early detection of COPD

CriteriaAt-risk population [10, 17, 19]Mild COPD [4, 5]Early diagnosis of COPD [15]Early COPD [3]
SymptomsCough, dyspnoea, phlegmDyspnoea 0–1 mMRC, CAT <10 pointsN/AN/A
ExposureAt least 10 pack-years cigarette smoke or biomass exposure [10, 20]At least 10 pack-year cigarette smoke or biomass exposureAt least 10 pack-year cigarette smokeAt least 10 pack-year cigarette smoke
Age yearsN/AN/AN/A<50
Progression to COPD∼30–40% [10, 19, 20]N/AN/ACurrently in study
Time to COPD diagnosis5 years
 FEV1/FVC ratioNormal<0.7<0.7<LLN
 FEV1 decline mL·year−1Variable [10, 19, 20]N/AN/A>60
CT scan>50% CT evidence of emphysema or airway wall thickening [10]N/AN/AVisual emphysema, air trapping or bronchial thickening

FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; CT: computed tomography; mMRC: modified Medical Research Council; CAT: COPD Assessment Test; N/A: not applicable; LLN: lower limit of normal.