title: Effect of long-term oxygen therapy on survival in patients with chronic obstructive pulmonary disease with moderate hypoxaemia.
abstract: BACKGROUND
  To date only two controlled studies have been published on the effects of domiciliary oxygen treatment on survival in patients with chronic obstructive pulmonary disease (COPD) with advanced respiratory failure. The survival in such patients despite oxygen treatment remains poor. The prescription of long term oxygen therapy (LTOT) in less severe disease remains controversial. The aim of this study was to evaluate the rationale for prescribing oxygen to patients with COPD with moderate hypoxaemia.
  
  
  METHODS
  One hundred and thirty five patients with COPD, with PaO2 7.4-8.7 kPa (56-65 mmHg) and advanced airflow limitation (mean (SD) forced expiratory volume in one second (FEV1) 0.83 (0.28) 1), were randomly allocated to a control (n = 67) and LTOT (n = 68) group. The patients were followed every three months for at least three years or until death.
  
  
  RESULTS
  The cumulative survival rate was 88% at one year, 77% at two years, and 66% at three years. No significant differences were found in survival rates between patients treated with LTOT and controls, nor did longer oxygen use (over 15 hours per day) improve survival. Younger age, better spirometric values, and higher body mass index predicted better survival.
  
  
  CONCLUSIONS
  Domiciliary oxygen treatment does not prolong survival in patients with COPD with moderate hypoxaemia. Airway limitation seems to determine survival in this group of patients.
authors.affiliation: Department of Respiratory Medicine, Institute of Tuberculosis and Lung Diseases, Warsaw, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Górecka
authors.forename: K
authors.initials: K
authors.lastname: Gorzelak
authors.forename: P
authors.initials: P
authors.lastname: Sliwiński
authors.forename: M
authors.initials: M
authors.lastname: Tobiasz
authors.forename: J
authors.initials: J
authors.lastname: Zieliński
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000401:mortality / Q000628:therapy*; D008173:Lung Diseases, Obstructive / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D016016:Proportional Hazards Models; D018709:Statistics, Nonparametric; D015996:Survival Rate; D017211:Treatment Failure