| Design | Multicentre randomised trial at six centres |
|---|---|
| Treatment | Continuous oxygen therapy |
| Control | 12-hour nocturnal oxygen therapy |
| Population | 203 patients with hypoxaemic chronic obstructive lung disease |
| Follow-up | At least 12 months, mean 19.3 months |
| Primary endpoint | Mortality |
| Result | Mortality in the nocturnal oxygen group was 1.94 times that in the continuous oxygen group (p=0.01). The difference was most striking in patients with carbon dioxide retention, poorer lung function, lower mean nocturnal oxygen saturation and greater brain dysfunction. |
| Secondary endpoints | Neuropsychological function, exercise capacity, pulmonary haemodynamics |
We conclude that in hypoxemic chronic obstructive lung disease, continuous O2 therapy is associated with a lower mortality than is nocturnal O2 therapy.
The trial authors, in the published abstract
Together with the MRC oxygen trial, this is why long-term oxygen therapy is prescribed for at least 15 hours a day and why more hours were long assumed to be better. REDOX has since tested that assumption directly and found no advantage to 24 hours over 15.
Continuous or nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease: a clinical trial. Nocturnal Oxygen Therapy Trial Group. Ann Intern Med 1980 Sep;93(3):391-8.