title: Pneumococcal Conjugated Vaccine Reduces the High Mortality for Community-Acquired Pneumonia in the Elderly: an Italian Regional Experience.
abstract: BACKGROUND
  Community-acquired pneumonia (CAP) is an important cause of illness and death worldwide, particularly among the elderly. Previous studies on the factors associated with mortality in patients hospitalized for CAP revealed a direct association between the type of microorganism involved, the characteristics of the patient and mortality. Vaccination status against pneumococcal disease was not considered. We conducted a retrospective analysis on the mortality rates after a first hospitalization for CAP in north-east Italy with a view to examining especially the role of anti-pneumococcal vaccination as a factor associated with pneumonia-related mortality at one year.
  
  
  METHODS
  Between 2012-2013, patients aged 65+ hospitalized with a primary diagnosis of CAP, identified based on International Classification of Diseases, Ninth Revision, Clinical Modification codes 481-486, were enrolled in the study only once. Patients were divided into three groups by pneumococcal vaccination status: 1) 13-valent pneumococcal conjugate vaccine (PCV13) prior to their hospitalization; 2) 23-valent pneumococcal polysaccharide vaccine (PPV23) within 5 years before hospitalization and 3) unvaccinated or PPV23 more than 5 years prior to admission. Gender, age, length of hospital stay and influenza vaccination were considered. Comorbidities were ascertained by means of a properly coded diagnosis. Every patient was followed up for 1 year and the outcome investigated was mortality for any cause and for pneumonia.
  
  
  RESULTS
  A total of 4,030 patient were included in the study; mean age at the time of admission to hospital was 84.3±7.7; 50.9% were female. 74.2% of subjects had at least one comorbidity; 73.7% has been vaccinated against influenza. Regard to pneumococcal vaccine, 80.4% of patients were not vaccinated, 14.5% vaccinated with PPV23 and 5.1% with PCV13. The 1-year survival rates after hospitalization for pneumonia were 83.6%, 85.9% and 89.3% in the unvaccinated, PPV23 and PCV13 groups, respectively. Regression analysis indicated that the risk of death due to pneumonia increased significantly with age (adjusted OR: 1.073; 1.061-1.085), shorter hospital stay (adjusted OR: 0.981; 0.971-0.990), and male gender (adjusted OR: 1.372; 1.165-1.616). The model also confirmed the pneumococcal 13-valent conjugated vaccine as an independent protective factor for mortality-related pneumonia (adjusted OR: 0.599; 0.390-0.921).
  
  
  CONCLUSIONS
  The main finding of our observational cohort study is a high mortality rate among elderly patients admitted to hospital for pneumonia. The present study suggests a protective role for PCV13 vaccination.
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Vincenzo
authors.identifier: http://orcid.org/0000-0001-6012-9453
authors.initials: V
authors.lastname: Baldo
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Cocchio
authors.affiliation: EuroHealth Net, Friuli Venezia Giulia Region Health Directorate, Udine, Italy.
authors.forename: Tolinda
authors.initials: T
authors.lastname: Gallo
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Furlan
authors.affiliation: EuroHealth Net, Friuli Venezia Giulia Region Health Directorate, Udine, Italy.
authors.forename: Pierantonio
authors.initials: P
authors.lastname: Romor
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Bertoncello
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Buja
authors.affiliation: Department of Cardiac, Thoracic, and Vascular Sciences, Hygiene and Public Health Unit, University of Padua, Padua, Italy.
authors.forename: Tatjana
authors.initials: T
authors.lastname: Baldovin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006760:Hospitalization; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007902:Length of Stay; D008297:Male; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology / Q000517:prevention & control*; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000276:immunology; D014611:Vaccination
chemical_list: C538862:13-valent pneumococcal vaccine; C414006:23-valent pneumococcal capsular polysaccharide vaccine; D022242:Pneumococcal Vaccines