Institutional members access full text with Ovid®

Share this article on:

Estimating the attributable mortality of ventilator-associated pneumonia from randomized prevention studies*

Melsen, Wilhelmina G. MD, MSc; Rovers, Maroeska M. PhD; Koeman, Mirelle MD, PhD; Bonten, Marc J. M. MD, PhD

doi: 10.1097/CCM.0b013e3182281f33
Review Articles

Objective: To assess the attributable mortality of ventilator-associated pneumonia using results from randomized controlled trials on ventilator-associated pneumonia prevention.

Data Sources: 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.

Study Selection: 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.

Data Extraction/Synthesis: 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%.

Conclusion: 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%.


From the Julius Center for Health Sciences and Primary Care (WGM, MMR, MJMB), the Department of Emergency Medicine and Infectious Diseases, and the Department of Medical Microbiology (MJMB), University Medical Center Utrecht, Utrecht, The Netherlands.

Currently address for Dr. Koeman: Department of Intensive Care, Haga Hospital, The Hague, The Netherlands.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site ( A supplemental table can be accessed through this link (Supplemental Digital Content 1,

Dr. Bonten is supported by The Netherlands Organization for Scientific Research (VICI NWO Grant 918.76.611).

The authors have not disclosed any potential conflicts of interest.

For information regarding this article, E-mail:

© 2011 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins