Table 1.

Spirometry criteria for chronic obstructive pulmonary disease severity

Severity	Criteria
Mild	FEV1≥80% predicted
Moderate	FEV1≥50% and <80% predicted
Severe	FEV1≥30% and <50% predicted
Very severe	FEV1<30% predicted

FEV₁=Forced expiratory volume in 1 s