title: Risk factors and antibiotic therapy in P. aeruginosa community-acquired pneumonia.
abstract: OBJECTIVE
  Current guidelines recommend empirical treatment against Pseudomonas aeruginosa in community-acquired pneumonia (CAP) patients with specific risk factors. However, evidence to support these recommendations is limited. We evaluate the risk factors and the impact of antimicrobial therapy in patients hospitalized with CAP due to P. aeruginosa.
  
  
  METHODS
  We performed a retrospective population-based study of >150 hospitals. Patients were included if they had a diagnosis of CAP and P. aeruginosa was identified as the causative pathogen. Univariate and multivariate analyses were performed using the presence of risk factors and 30-day mortality as the dependent measures.
  
  
  RESULTS
  Seven hundred eighty-one patients with P. aeruginosa pneumonia were identified in a cohort of 62 689 patients with pneumonia (1.1%). Of these, 402 patients (0.6%) were included in the study and 379 (0.5%) were excluded due to health care-associated pneumonia or immunosuppression. In patients with CAP due to P. aeruginosa, 272 (67.8%) had no documented risk factors. These patients had higher rates of dementia and cerebrovascular disease. Empirical antibiotic therapy against P. aeruginosa within the first 48 h of presentation was independently associated with lower 30-day mortality in patients with CAP due to P. aeruginosa (hazard ratio (HR) 0.42, 95% confidence interval (CI): 0.23-0.76) and in patients without risk factors for P. aeruginosa CAP (HR 0.40, 95% CI: 0.21-0.76).
  
  
  CONCLUSIONS
  Risk factor recommended by current guidelines only detect one third of the patients admitted with CAP due to P. aeruginosa. Risk factors did not define the whole benefit observed due to empirical therapy covering P. aeruginosa.
authors.affiliation: Respiratory Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; Sant Pau Biomedical Research Institute (IIB Sant Pau), Barcelona, Spain; Division of Pulmonary and Critical Care, University of Texas Health Science Center, San Antonio, Texas, USA.
authors.forename: Oriol
authors.initials: O
authors.lastname: Sibila
authors.forename: Elena
authors.initials: E
authors.lastname: Laserna
authors.forename: Diego Jose
authors.initials: DJ
authors.lastname: Maselli
authors.forename: Juan Felipe
authors.initials: JF
authors.lastname: Fernandez
authors.forename: Eric M
authors.initials: EM
authors.lastname: Mortensen
authors.forename: Antonio
authors.initials: A
authors.lastname: Anzueto
authors.forename: Grant
authors.initials: G
authors.lastname: Waterer
authors.forename: Marcos I
authors.initials: MI
authors.lastname: Restrepo
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011014:Pneumonia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011159:Population Surveillance; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification*; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: Pseudomonas aeruginosa; antibiotic treatment; community-acquired pneumonia; risk factor