Table 2 Assessment of severity of airflow obstruction in chronic obstructive pulmonary disease according to forced expiratory volume 1 s (FEV₁) % predicted (% pred)

FEV₁ % pred	Category^#
≥80	Mild
50–79	Moderate
30–49	Severe
<30	Very severe

^#: values are post-bronchodilator and used in combination with an FEV₁/FVC ratio of <0.7.