The left panel of this Figure shows the changes of 6-min walk distance from the study^[9] in the previous Figure, and again it is clear that the patients receiving nocturnal NIV in addition to pulmonary rehabilitation improved 6-min walk distance over time, whereas there was no significant improvement over time in the control group.  

The right panel shows results for lung function parameters, and again the patients receiving nocturnal NIV in addition to pulmonary rehabilitation had better values than the control group receiving only pulmonary rehabilitation without nocturnal NIV.