title: Home oxygen therapy reduces risk of hospitalisation in patients with chronic obstructive pulmonary disease: a population-based retrospective cohort study, 2005-2012.
abstract: OBJECTIVE
  This study evaluated the effect of home oxygen therapy (HOT) on hospital admissions in chronic obstructive pulmonary disease (COPD) patients.
  
  
  METHODS
  Using nationwide health insurance claims from 2002-2012, we conducted a longitudinal population-based retrospective cohort study.
  
  
  METHODS
  Individuals who were aged 40 years or above and newly diagnosed with COPD in 2005.
  
  
  METHODS
  The primary outcome was total number of hospitalisations during the study period. Participants were matched using HOT propensity scores and were stratified by respiratory impairment (grade 1: FEV1 ≤25% or PaO2 ≤55 mm Hg; grade 2: FEV1 ≤30% or PaO2 56-60 mm Hg; grade 3: FEV1 ≤40% or PaO2 61-65 mm Hg; 'no grade': FEV1 or PaO2 unknown), then a negative binomial regression analysis was performed for each group.
  
  
  RESULTS
  Of the 36,761 COPD patients included in our study, 1330 (3.6%) received HOT. In a multivariate analysis of grade 1 patients performed before propensity score matching, the adjusted relative risk of hospitalisation for patients who did not receive HOT was 1.27 (95% CI 1.01 to 1.60). In a multivariate analysis of grade 1 patients performed after matching, the adjusted relative risk for patients who did not receive HOT was 1.65 (95% CI 1.25 to 2.18). In grade 2 or grade 3 patients, no statistical difference in hospital admission risk was detected. In the 'no grade' group of patients, HOT was associated with an increased risk of hospitalisation.
  
  
  CONCLUSIONS
  HOT reduces the risk of hospital admission in COPD patients with severe hypoxaemia. However, apart from these patients, HOT use is not associated with hospital admissions.
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Kyoung Hee
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Biostatistics, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.affiliation: Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea Graduate School of Public Health, Yonsei University, Seoul, Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Sun Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Han
authors.affiliation: Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea Department of Preventive Medicine, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Park
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D006699:Home Care Services; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D012306:Risk; D013997:Time Factors
keywords: PRIMARY CARE; RESPIRATORY MEDICINE (see Thoracic Medicine)