Figure 5.

Effect of controlled trials of inhaled pharmacotherapy (CT) and lung volume reduction (NETT) on the 6-minute-walk distance (6MWD) and FEV₁. The 6MWD, expressed on the horizontal axis as percentage change from baseline (top) or as absolute distance in meters (bottom), increased proportionally to the improvement in FEV₁ (vertical axis) in patients included in the National Emphysema Therapy Trial (NETT). The decrease in FEV₁ shown in the lower portion of the graphs shows that overall, there was a decrease in lung function and there was no relation between change in 6MWD and lung function in the pharmacologic trials (CT).