Fig. 42:  This Figure lists some of the challenges to conducting this trial, which closed in August 2015.  These challenges explain why this study, which was designed to be conducted in 3 years in fact required 6 years to complete.  First, participant recruitment was much more difficult because some patients and physicians refused randomization to supplemental oxygen.  Another factor was that, because CMS was the provider that paid for this study, participants needed to have enrolled in Medicare B coverage. 

However one of the major factors was the polarization, in terms of both patients’ and providers’ perspectives, between those who would rather do anything than wear oxygen supplementation hardware, as opposed to other patients and providers who believe that oxygen is a panacea. 

In the end hopefully NOTT will help to provide guidance as to what the benefits of supplemental oxygen are.  As a result of insufficient funds looking at some of the other exploratory or mechanistic potential benefits of supplemental oxygen (eg, what oxygen does in sleep, or to oxidant stress or other molecular pathways of injury or repair to the lung, and/or to comprehensively phenotype participants in terms of radiographic dimensions or the presence of emphysema, etc.) might have been beneficial but these avenues of inquiry had to be eliminated from the study because of limitations in the monies that could be allocated to perform this project.