title: Impact of the pneumococcal vaccine on long-term morbidity and mortality of adults at high risk for pneumonia.
abstract: BACKGROUND
  There is debate surrounding the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPV). We determined whether PPV was associated with reduced mortality or additional hospitalization for vaccine-preventable infections in patients previously hospitalized for community-acquired pneumonia (CAP).
  
  
  METHODS
  From 2000 through 2002, adults with CAP admitted to the hospital in Edmonton, Alberta, Canada, were enrolled in a population-based cohort. Postdischarge outcomes during 5 years were ascertained using administrative databases. The primary outcome was the composite of all-cause mortality or additional hospitalization for vaccine-preventable infections. Proportional hazards analysis was used to determine the association between PPV use and outcomes.
  
  
  RESULTS
  A total of 2950 patients were followed up for a median of 3.8 years. The mean patient age was 68 years; 52% were male. One-third (n = 956) received PPV: 667 (70%) before and 289 (30%) during hospitalization. After discharge, 1404 patients (48%) died, 504 (17%) were admitted with vaccine-preventable infections, and 1626 (55%) reached the composite outcome of death or infection. PPV was not associated with reduced risk of the composite outcome (589 [62%] vs 1037 [52%] for those unvaccinated; adjusted hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.79-1.04). Results were not altered in sensitivity analyses using propensity scores (adjusted HR, 0.91; 95% CI, 0.79-1.04), restricting the sample to patients 65 years or older (adjusted HR, 0.90; 95% CI, 0.77-1.04), or considering only those who received PPV at discharge (adjusted HR, 0.84; 95% CI, 0.71-1.00).
  
  
  CONCLUSIONS
  One-half of patients discharged from the hospital after pneumonia die or are subsequently hospitalized with a vaccine-preventable infection within 5 years. PPV was not associated with a reduced risk of death or hospitalization. Better pneumococcal vaccination strategies are urgently needed.
authors.affiliation: Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada. johnsj48@mcmaster.ca
authors.forename: Jennie
authors.initials: J
authors.lastname: Johnstone
authors.forename: Dean T
authors.initials: DT
authors.lastname: Eurich
authors.forename: Jasjeet K
authors.initials: JK
authors.lastname: Minhas
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Marrie
authors.forename: Sumit R
authors.initials: SR
authors.lastname: Majumdar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000276:immunology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D017063:Outcome Assessment, Health Care; D022242:Pneumococcal Vaccines; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D016016:Proportional Hazards Models; D012307:Risk Factors
chemical_list: D022242:Pneumococcal Vaccines