title: Comparison of clinical characteristics and outcomes between aspiration pneumonia and community-acquired pneumonia in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) patients often have dysphagia through age and several co-morbidities, leading to aspiration pneumonia (AsP). COPD patients also have increased risk of developing community-acquired pneumonia (CAP). Using a national inpatient database in Japan, we aimed to compare clinical characteristics and outcomes between AsP and CAP in COPD patients and to verify the factors that affect in-hospital morality.
  
  
  METHODS
  We retrospectively collected data on COPD patients (age ≥40 years) who were admitted for AsP or CAP in 1,165 hospitals across Japan between July 2010 and May 2013. We performed multivariable logistic regression analyses to examine the association of various factors with all-cause in-hospital mortality for AsP and CAP.
  
  
  RESULTS
  Of 87,330 eligible patients, AsP patients were more likely to be older, male and have poorer general condition and more severe pneumonia than those with CAP. In-hospital mortality in the AsP group was 22.7% and 12.2% in the CAP group. After adjustment for patient background, AsP patients had significantly higher mortality than CAP patients (adjusted odds ratio, 1.19; 95% confidence interval, 1.08-1.32). Subgroup analyses showed higher mortality to be associated with male gender, underweight, dyspnea, physical disability, pneumonia severity, and several co-morbidities. Further, older age and worse level of consciousness were associated with higher mortality in the CAP group, whereas those were not associated in the AsP group.
  
  
  CONCLUSIONS
  Clinical characteristics differed significantly between AsP and CAP in COPD patients. AsP patients had significantly higher mortality than those with CAP.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. YAMAUCHIY-INT@h.u-tokyo.ac.jp.|Division for Health Service Promotion, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. YAMAUCHIY-INT@h.u-tokyo.ac.jp.
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, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. yasunagah-tky@umin.ac.jp.
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, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. ptmatsui-tky@umin.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsui
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. w-hasegawa@umin.ac.jp.
authors.forename: Wakae
authors.initials: W
authors.lastname: Hasegawa
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. jo-taisuke@umin.ac.jp.|Division for Health Service Promotion, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan. jo-taisuke@umin.ac.jp.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Jo
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. tkmkztk-tky@umin.ac.jp.
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, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. kfushimi.hci@tmd.ac.jp.
authors.forename: Kiyohide
authors.initials: K
authors.lastname: Fushimi
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. takahide-tky@umin.ac.jp.
authors.forename: Takahide
authors.initials: T
authors.lastname: Nagase
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D017714:Community-Acquired Infections / Q000401:mortality*; D015897:Comorbidity; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011015:Pneumonia, Aspiration / Q000401:mortality*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012189:Retrospective Studies