title: Effect of pneumococcal vaccination in hospitalized adults with community-acquired pneumonia.
abstract: BACKGROUND
  Although 23-valent polysaccharide pneumococcal vaccine (PPV) does not prevent community-acquired pneumonia (CAP), it might still improve outcomes in those who develop pneumonia. We tested this hypothesis using a population-based cohort of hospitalized patients with CAP.
  
  
  METHODS
  From 2000 to 2002, we prospectively collected data on all adults with CAP admitted to 6 hospitals in Capital Health, the largest integrated health delivery system in Canada. Polysaccharide pneumococcal vaccine status was ascertained by interview, medical record review, and contact with physicians and community health offices. The primary outcome was the composite of in-hospital mortality or intensive care unit (ICU) admission. Multivariable regression was used to determine the independent association between PPV use and outcomes, after adjusting for patient characteristics, pneumonia severity, and propensity scores.
  
  
  RESULTS
  Of the 3415 patients with CAP (median age, 75 years), 46% were female, 62% had severe pneumonia, and 22% had prior PPV. Overall, 624 patients died or were admitted to an ICU. Polysaccharide pneumococcal vaccine was protective from reaching this composite end point (73/760 [10%] vs 551/2655 [21%] for unvaccinated patients; P < .001), mostly a result of reduced ICU admission (2/760 [<1%] vs 349/2655 [13%]). The propensity-adjusted odds of death or ICU admission was 0.62 (95% confidence interval, 0.42-0.92; P = .02) for patients who had received PPV. Only 215 of 2416 patients (9%) eligible for PPV at hospital discharge were vaccinated.
  
  
  CONCLUSIONS
  Patients with CAP who had prior PPV had about a 40% lower rate of mortality or ICU admission compared with those who were not vaccinated. This provides additional support for recommending PPV to those at risk of pneumonia.
authors.affiliation: Department of Medicine, University of Alberta, 2E3.07 Walter Mackenzie Health Sciences Centre, University of Alberta Hospital, 8440 112th Street, Edmonton, Alberta, Canada.
authors.forename: Jennie
authors.initials: J
authors.lastname: Johnstone
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Marrie
authors.forename: Dean T
authors.initials: DT
authors.lastname: Eurich
authors.forename: Sumit R
authors.initials: SR
authors.lastname: Majumdar
mesh_terms: D000368:Aged; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D022242:Pneumococcal Vaccines; D011014:Pneumonia / Q000401:mortality / Q000503:physiopathology* / Q000517:prevention & control; D011446:Prospective Studies; D014611:Vaccination
chemical_list: D022242:Pneumococcal Vaccines