title: Comparison of in-hospital mortality in patients with COPD, asthma and asthma-COPD overlap exacerbations.
abstract: OBJECTIVE
  Obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), have airflow limitation associated with chronic inflammation. Using a national inpatient database in Japan, we aimed to evaluate factors affecting in-hospital mortality in patients with asthma, COPD or asthma-COPD overlap (ACO).
  
  
  METHODS
  We retrospectively collected data for inpatients (age >40 years) with exacerbation of COPD and/or asthma in 1073 hospitals across Japan between July 2010 and May 2013. We performed multivariable logistic regression analysis to examine the association of various factors with all-cause in-hospital mortality, including diagnosis of ACO, asthma alone and COPD alone.
  
  
  RESULTS
  Of 30 405 eligible patients, in-hospital mortality in patients with ACO, asthma alone and COPD alone was 2.3%, 1.2% and 9.7%, respectively. COPD patients had a significantly higher mortality than ACO patients (odds ratio 1.96; 95% confidence interval: 1.38-2.79); patients with asthma alone showed lower mortality (0.70; 0.50-0.97). Higher mortality was also significantly associated with older age, male gender, lower body mass index, more severe dyspnoea, lower level of consciousness, worse activities of daily life and higher daily dose of corticosteroids.
  
  
  CONCLUSIONS
  Asthma alone was associated with lower mortality, but COPD alone was associated with higher mortality than ACO.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.|Division for Health Service Promotion, The University of Tokyo, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
authors.affiliation: Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Wakae
authors.initials: W
authors.lastname: Hasegawa
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.|Division for Health Service Promotion, The University of Tokyo, Tokyo, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Jo
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Takami
authors.affiliation: Department of Health Policy and Informatics, Tokyo Medical and Dental University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takahide
authors.initials: T
authors.lastname: Nagase
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000401:mortality* / Q000503:physiopathology; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors
keywords: asthma; asthma-chronic obstructive pulmonary disease overlap syndrome; chronic obstructive pulmonary disease; in-hospital mortality; obstructive airway disease