title: Clinical features, etiology and outcomes of community-acquired pneumonia in patients with chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Community-acquired pneumonia (CAP) is a frequent complication of chronic obstructive pulmonary disease (COPD), but previous studies are often contradictory.
  
  
  OBJECTIVE
  We aimed to ascertain the characteristics and outcomes of CAP in patients with COPD as well as to determine the risk factors for mortality and Pseudomonas aeruginosa pneumonia in COPD patients with CAP. We also describe the etiology and outcomes of CAP in COPD patients receiving chronic oxygen therapy at home and those receiving inhaled steroids.
  
  
  METHODS
  An observational analysis of a prospective cohort of hospitalized adults with CAP (1995-2011) was performed.
  
  
  RESULTS
  We documented 4121 CAP episodes, of which 983 (23.9%) occurred in patients with COPD; the median FEV1 value was 50%, and 57.8% were classified as stage III or IV in the GOLD classification. Fifty-eight per cent of patients were receiving inhaled steroids, and 14.6% chronic oxygen therapy at home. Patients with COPD presented specific clinical features. S. pneumoniae was the leading causative organism overall, but P. aeruginosa was more frequent in COPD (3.4 vs. 0.5%; p<0.001). Independent risk factors for case-fatality rate in patients with COPD were multilobar pneumonia, P. aeruginosa pneumonia, and high-risk PSI classes. Prior pneumococcal vaccination was found to be protective. FEV1 was an independent risk factor for P. aeruginosa pneumonia.
  
  
  CONCLUSIONS
  CAP in patients with COPD presents specific characteristics and risk factors for mortality. Prior pneumococcal vaccine has a beneficial effect on outcomes. P. aeruginosa pneumonia is associated with low FEV1 values and poor prognosis.
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Gómez-Junyent
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain; REIPI (Spanish Network for the Research in Infectious Diseases), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Garcia-Vidal
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain; REIPI (Spanish Network for the Research in Infectious Diseases), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Viasus
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain.
authors.forename: Pere
authors.initials: P
authors.lastname: Millat-Martínez
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain.
authors.forename: Antonella
authors.initials: A
authors.lastname: Simonetti
authors.affiliation: Department of Respiratory Medicine, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain.
authors.forename: Ma Salud
authors.initials: MS
authors.lastname: Santos
authors.affiliation: Department of Microbiology, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Ardanuy
authors.affiliation: Department of Respiratory Medicine, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain; REIPI (Spanish Network for the Research in Infectious Diseases), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Dorca
authors.affiliation: Department of Infectious Diseases, Hospital Universitari de Bellvitge, University of Barcelona, and Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona, Spain; REIPI (Spanish Network for the Research in Infectious Diseases), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Carratalà
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D011014:Pneumonia / Q000175:diagnosis* / Q000209:etiology; D011379:Prognosis; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000628:therapy; D012307:Risk Factors; D016896:Treatment Outcome