title: Estimating the attributable mortality of ventilator-associated pneumonia from randomized prevention studies.
abstract: OBJECTIVE
  To assess the attributable mortality of ventilator-associated pneumonia using results from randomized controlled trials on ventilator-associated pneumonia prevention.
  
  
  METHODS
  A systematic search was performed in PubMed, Embase, Web of Science, and Cochrane Library from their inception until July 2010. In addition, a reference and related article search was performed.
  
  
  METHODS
  Randomized ventilator-associated pneumonia prevention studies in which all patients were mechanically ventilated and from which ventilator-associated pneumonia and mortality rates of intervention and control group could be extracted were included.
  
  
  METHODS
  Fifty-three papers were identified describing 58 comparisons. Statistical significant reductions in ventilator-associated pneumonia incidences were reported in 20 of the 58 comparisons, whereas none of these trials reported a significant reduction of mortality. Pooled estimates of the relative risk reductions of both ventilator-associated pneumonia and mortality were calculated and the attributable mortality was estimated as the ratio between the relative risk reductions of mortality and ventilator-associated pneumonia. Effects of study quality, diagnostic methods used, and effectiveness of preventing ventilator-associated pneumonia on the mortality rate of ventilator-associated pneumonia were assessed in subgroup analyses. The overall attributable mortality of ventilator-associated pneumonia was estimated as 9%. In subgroup analyses, the attributable mortality varied between 3% and 17%.
  
  
  CONCLUSIONS
  Based on the results of 58 randomized studies on ventilator-associated pneumonia prevention, the attributable mortality rate of ventilator-associated pneumonia was estimated to be 9% and ranged between 3% and 17% in subgroup analyses. Together with the results of other recent studies, there is cumulative evidence that the attributable mortality resulting from ventilator-associated pneumonia is approximately 10%.
authors.affiliation: Julius Center for Health Sciences and Primary Care, the Department of Emergency Medicine and Infectious Diseases, University Medical Center Utrecht, Utrecht, The Netherlands. W.G.Melsen@umcutrecht.nl
authors.forename: Wilhelmina G
authors.initials: WG
authors.lastname: Melsen
authors.forename: Maroeska M
authors.initials: MM
authors.lastname: Rovers
authors.forename: Mirelle
authors.initials: M
authors.lastname: Koeman
authors.forename: Marc J M
authors.initials: MJ
authors.lastname: Bonten
mesh_terms: D006801:Humans; D053717:Pneumonia, Ventilator-Associated / Q000401:mortality* / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D040242:Risk Reduction Behavior