A Cochrane review «Domiciliary oxygen for chronic obstructive pulmonary disease»1 «Cranston JM, Crockett AJ, Moss JR et al. Domiciliary oxygen for chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2005;(4):CD001744 [Last assessed as upto-date: 15 January 2007]. »1 included 6 studies with a total of 567 subjects. With continuous oxygen therapy versus nocturnal oxygen therapy, there was a significant improvement in mortality after 24 months (Peto OR 0.45, 95% CI 0.25 to 0.81; 1 trial, n=203). With domiciliary oxygen therapy versus no oxygen therapy, there was a significant improvement over five years in mortality (Peto OR 0.42, 95% CI 0.18 to 0.98; 1 trial, n=87). With nocturnal oxygen versus no oxygen therapy in patients with COPD and arterial desaturation at night, there was no difference in mortality (2 trials). With long-term oxygen therapy versus no oxygen therapy in COPD patients with mild to moderate hypoxaemia, there was no effect on survival for up to three years of follow up (2 trials).
Comment: The quality of evidence is downgraded by indirectness of evidence. The relatively small numbers of patients, the young age of participants and the lack of comorbidities in most of the above studies raises concerns about the applicability of the survival outcomes to current clinical situations