Although it was clearly rational to increase the arterial oxygen tension of patients with chronic hypoxaemia, it was not until the publication of two key randomised controlled trials on the effects of long term oxygen therapy (LTOT) in the early 1980s^1,2 that home oxygen services were developed in many countries where they now form an integral part of the management of chronic respiratory disability. Although these trials addressed the role of oxygen in prolonging life for patients with COPD, three main forms of home oxygen services have developed with rather different goals:

1. LTOT is prescribed for patients with chronic hypoxaemia (Pao₂ ⩽7.3 kPa (55 mm Hg)) for continuous use at home and is one of the few interventions to date that has been shown to reduce mortality in patients with COPD.

2. Ambulatory oxygen therapy refers to the provision of oxygen therapy with a portable device during exercise and daily activities.

3. Short burst oxygen therapy refers to the intermittent use of oxygen at home, usually provided by stationary cylinders for periods of 10–20 minutes at a time to relieve the symptom of breathlessness. Although short burst oxygen is widely prescribed in the UK for relief of breathlessness, there is little evidence currently available for its benefit^3,4 and delivery of cylinders to the home is costly.

In the UK, provision of LTOT through the prescription of home oxygen concentrators became available in November 1985 and since then concentrators have been installed and maintained by contractors.⁵ Although in Scotland LTOT can be prescribed in secondary care, in England and Wales oxygen concentrators can only be prescribed by primary care physicians. However, this prescription usually takes place on the recommendation of secondary care physicians and concentrators are …