Airflow limitation severity in patients with COPD and FEV1/FVC < 0.70 can be classified based on post-bronchodilator FEV1 (2): Mild: ≥ 80% of predicted Moderate: 50% to 79% of predicted Severe: 30% to 49% of predicted Very severe: < 30% of predicted Additional pulmonary function testing is necessary only in specific circumstances, such as before lung volume reduction procedures.