Fig. (1) Relationship between proximal (increase in FEV₁) and distal (increase in IC) response to bronchodilator. Dotted lines are 12% increase in FEV₁ or IC as compared to baseline value. There was a non significant relationship between the two responses (p=0.465). Three patients, two with flow-responder group and one with non responder group, depicted a significant FVC response without significant IC response.