title: Long-Term Oxygen Therapy 24 vs 15 h/day and Mortality in Chronic Obstructive Pulmonary Disease.
abstract: Long-term oxygen therapy (LTOT) ≥ 15 h/day improves survival in hypoxemic chronic obstructive pulmonary disease (COPD). LTOT 24 h/day is often recommended but may pose an unnecessary burden with no clear survival benefit compared with LTOT 15 h/day. The aim was to test the hypothesis that LTOT 24 h/day decreases all-cause, respiratory, and cardiovascular mortality compared to LTOT 15 h/day in hypoxemic COPD. This was a prospective, observational, population-based study of COPD patients starting LTOT between October 1, 2005 and June 30, 2009 in Sweden. Overall and cause-specific mortality was analyzed using Cox and Fine-Gray regression, controlling for age, sex, prescribed oxygen dose, PaO2 (air), PaCO2 (air), Forced Expiratory Volume in one second (FEV1), WHO performance status, body mass index, comorbidity, and oral glucocorticoids. A total of 2,249 included patients were included with a median follow-up of 1.1 years (interquartile range, 0.6-2.1). 1,129 (50%) patients died and no patient was lost to follow-up. Higher LTOT duration analyzed as a continuous variable was not associated with any change in mortality rate (hazard ratio [HR] 1.00; (95% confidence interval [CI], 0.98 to 1.02) per 1 h/day increase above 15 h/day. LTOT exactly 24 h/day was prescribed in 539 (24%) patients and LTOT 15-16 h/day in 1,231 (55%) patients. Mortality was similar between the groups for all-cause, respiratory and cardiovascular mortality. In hypoxemic COPD, LTOT 24 h/day was not associated with a survival benefit compared with treatment 15-16 h/day. A design for a registry-based randomized trial (R-RCT) is proposed.
authors.affiliation: Department of Clinical Sciences, Division of Respiratory Medicine & Allergology, Lund University, Lund, Sweden.
authors.forename: Zainab
authors.identifier: http://orcid.org/0000-0003-1434-5715
authors.initials: Z
authors.lastname: Ahmadi
authors.affiliation: Department of Respiratory Medicine, School of Medical Sciences, Örebro University, Örebro, Sweden.
authors.forename: Josefin
authors.initials: J
authors.lastname: Sundh
authors.affiliation: Department of Statistics, Uppsala University, Uppsala, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Bornefalk-Hermansson
authors.affiliation: Department of Clinical Sciences, Division of Respiratory Medicine & Allergology, Lund University, Lund, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Ekström
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome