Fig. 21:  More recent data by Turner et al^[13] suggest that perhaps individuals who use long-term oxygen therapy may be a sicker group of patients.  As seen in this Figure, they evaluated oxygen prescription in relation to hospitalization in patients with COPD and found, looking at the 189 patients who used long-term oxygen therapy (LTOT) compared to the 706 patients who did not, the patients on LTOT were more likely to be admitted to the hospital and they stayed in the hospital longer.  They were also more severely obstructed by FEV₁ in absolute and by percent predicted, and they were of similar age.  So, overall these data suggest that perhaps people who use long-term oxygen therapy continuously are patients who are more impaired.