Classification of copd by severity Stage o( at risk Chronic cough and sputum production Contact with harmful factors FEV1/FVC>70% Stage I( mild) FEV1/FVC <70% FEVI 8 80 predicted usually, but not always, chronic cough andClassification of COPD by Severity • Stage 0 ( at risk) – Chronic cough and sputum production – Contact with harmful factors – FEV1/FVC > 70% • Stage I( mild) – FEV1/FVC < 70% – FEV1  80 % predicted – usually, but not always, chronic cough and sputum production