FIG. 35:  This Figure is a CONSORT diagram for the Long-Term Oxygen Treatment Trial (LOTT).^[23]  From a large pool of patients identified as possible candidates, 1759 signed a consent form and started formal screening.  Of these, 1021 patients were excluded (most because they did not desaturate enough, either at rest or on ambulation, or because their FEV₁ was too high or they had no evidence of obstruction).  After some other patients were excluded for other reasons (not shown), 738 patients that were randomized in a 1:1 allocation to either supplemental oxygen (n=368) or no supplemental oxygen (n=370).  Of the patients assigned to receive supplemental oxygen, 220 (60%) were prescribed continuous 24-h oxygen and 148 (40%) were prescribed oxygen only during activity and sleep.