Fig. 16:  This Figure^[10] shows the survival benefits of long-term oxygen therapy in patients with COPD and mild-to-moderate (but not severe) hypoxemia.  The Figure summarizes the results from the only two studies that exist, the first by Gorecka in 1997 with 135 subjects and the second by Haidl in 2004 looking at 28 subjects.  In Gorecka’s study (upper blue panel), patients had a PaO₂ of 56–65 mmHg, not the ≤55 mmHg seen in the MRC and NOTT studies.  In Haidl’s study (lower blue panel) the patients had a PaO₂ >55 mmHg.  As shown in this Figure, the Goreka and Haidl studies in aggregate show that mortality is not better with oxygen therapy; in fact, it appears that the mortality effect was actually worse with oxygen therapy, although this analysis was underpowered to achieve statistical significance.