Table 2.
Long-Term Oxygen Treatment Trial hypotheses
| For patients who have COPD and 1) moderate resting desaturation or 2) normal resting saturation and moderate desaturation during exercise, treatment with supplemental oxygen, in comparison with no treatment with supplemental oxygen, will lead to: |
| Primary |
| Ha 1: Increased time to all-cause mortality or all-cause hospitalization |
| Secondary |
| Ha 2: Increased time to all-cause mortality |
| Ha 3: Increased time to all-cause hospitalization |
| Ha 4: Improved disease-specific quality of life |
| Ha 5: Improved preference-weighted health-related quality of life |
| Ha 6: Decreased disease impact (e.g., reduced dyspnea, longer 6-min walk distance, reduced COPD exacerbation rate) |
| Ha 7: Improved quality-adjusted survival |
| Ha 8: Lower health care utilization |
| Ha 9: Better maintenance of nutritional status (e.g., body mass index) |
| Ha 10: Improved general quality of life |
| Ha 11: Better sleep quality |
| Ha 12: Less depression and less anxiety |
| Ha 13: Delayed onset of severe hypoxemia (defined as room air SpO2 88% or less) |
| Ha 14: Lower risk of cardiovascular disease outcomes (e.g., acute coronary syndrome, chronic heart failure exacerbation, mortality secondary to these outcomes) |
| Ha 15: Longer survival and better outcomes in those with greater adherence to supplemental oxygen use in comparison with those with lesser adherence |
| Exploratory |
| Analyses will be performed to test the consistency of treatment effects across subgroups defined by baseline demographic and clinical characteristics. Subgroups to be examined include but are not limited to those defined by age, race/ethnicity, sex, oxyhemoglobin saturation during exercise, lung function (e.g., FEV1), and smoking status |
Definition of abbreviations: COPD = chronic obstructive pulmonary disease; SpO2 = oxyhemoglobin saturation by pulse oximetry.
Bold type items added as protocol amendment #1 (see Figure 2).