Change in requirement for oxygen supplementation based on daily assessment of flow (LPM or %Fi O2) and delivery device (cannula, mask, CPAP/BiPAP, ventilator);Change in respiratory symptoms (cough, shortness of breath, and fatigue) determined by data extraction from medical record, self-assessment by subject, or subject survey as appropriate for stage of the study.

Change in requirement for oxygen supplementation based on daily assessment of flow (LPM or %Fi O2) and delivery device (cannula, mask, CPAP/BiPAP, ventilator);Change in respiratory symptoms (cough, shortness of breath, and fatigue) determined by data extraction from medical record, self-assessment by subject, or subject survey as appropriate for stage of the study.