To compare the efficacy of long-term use of nocturnal oxygen therapy (12 hours) with that of continuous, low-flow oxygen therapy (24 hours) in patients with chronic hypoxic lung disease.

BACKGROUND:

Chronic obstructive pulmonary disease is a major health problem in the United States. In 1975, it was the sixth leading cause of death. The economic impact of the disease in 1972 amounted to $803 million in the direct costs of disability treatment, $3.05 billion in disability costs, and $645 million in lost earnings due to premature death.

Motivated in part by the significant toll of this disease, a conference on the Scientific Basis of Respiratory Therapy, co-sponsored by the American Thoracic Society and the Division of Lung Diseases, examined the current status of the use of oxygen therapy in chronic lung disease. The proceedings of the conference, published in the American Review of Respiratory Disease (Vol. 110, No. 6, December 1974), included a recommendation for clinical studies that would provide a critical assessment of the role of nocturnal oxygen therapy in the treatment of patients with chronic obstructive pulmonary disease. Low-flow oxygen, administered continuously, was known to benefit some patients with chronic hypoxic lung disease. However, low-flow oxygen administration for long periods of time is cumbersome, confining, and expensive. If nocturnal oxygen administration could be unequivocally demonstrated to be efficacious, then the advantages of convenience and cost would have a favorable impact on treatment of patients, and a rationale could be developed for testing this therapy in a larger group of patients.

The Planning Phase of the trial was initiated in September 1976. Patient recruitment began in May 1977. The Recruitment Phase lasted 24 months. The 203 patients in the trial were assigned randomly to nocturnal oxygen therapy (home) or continuous low-flow oxygen therapy.

DESIGN NARRATIVE:

Randomized, fixed sample. Two hundred and three patients were randomly assigned to at-home treatments of continuous oxygen therapy or nocturnal oxygen therapy. Endpoints related to quality of life, neuropsychological function, and respiratory function and capacity. Intervention lasted for 6 months to 3 years, with an average intervention of 19.3 months.

Men and women, ages 35 to 70, who had severe chronic obstructive lung disease requiring supplemental oxygen therapy.