There is no widely accepted standard definition for Ventilator Associated Pneumonia (VAP). The reliability of the current definitions in use remains controversial. Our objective was to assess the reliability of six commonly used VAP definitions: The Loose, The Rigorous, The Modified Clinical Pulmonary Infection Score (CPIS), The Canadian Critical Care Trials Group (CCCTG), The International Sepsis Forum Consensus (ISFC) and The Center for Disease Control and Prevention (CDC).


We examined the electronic health records of all the consecutively admitted adult patients at our institution who received invasive mechanical ventilation (IMV) for ≥ 48 hours, from January 2006 through December 2006.Patients were excluded if they developed pneumonia within the first 48 hours or if they had a tracheostomy before IMV. Two expert intensivists independently reviewed the following data for each patient: indications and duration of IMV, vital signs, oxygen requirements, frequency of respiratory suctioning, amount, color and consistency of secretion, ventilator settings, leukocyte count, microbiologic and radiographic data. Interreviewer reliability in diagnosing VAP independently were compared using Cohen’s-Kappa statistics.


A total of 115 patients met the initial inclusion criteria of which 47 patients were excluded (40 had pneumonia on presentation, 6 developed pneumonia within 48 hours and 1 had a tracheostomy on admission). The inter-reviewer agreement Kappa for the Loose, the Rigorous, CPIS, CCCTG, ISFC and CDC definitions for VAP were 0.22, 0.49, 0.33, 0.41, 0.38 and 0.68 respectively.


The CDC definition of VAP proved to be statistically more reliable than other tested definitions of VAP, as demonstrated by the lowest interrater variability between two independent reviewers.

Conflict(s) of Interest

All authors have no conflicts of interest to disclose

References with DOI

1. Combes A, Luyt CE, Trouillet JL, Chastre J. Controversies in ventilator-associated pneumonia. Semin Respir Crit Care Med. 2010;31:47-54. https://doi.org/10.1055/s-0029-1246288

2. Edwards JR, Peterson KD, Mu Y, et al. National Healthcare Safety Network (NHSN) report: data summary for 2006 through 2008, issued December 2009. Am J Infect Control. 2009;37:783-805. https://doi.org/10.1016/j.ajic.2009.10.001

3. Dudeck MA, Horan TC, Peterson KD, et al. National Healthcare Safety Network report, data summary for 2011, device-associated module. Am J Infect Control. 2013;41:286-300. https://doi.org/10.1016/j.ajic.2011.04.011

4. Chinsky KD. Ventilator-associated pneumonia: is there any gold in these standards? Chest. 2002;122:1883- 1885. https://doi.org/10.1378/chest.122.6.1883

5. Klompas M. Does this patient have ventilator-associated pneumonia? JAMA. 2007;297:1583-1593. https://doi.org/10.1001/jama.297.14.1583

6. Klompas M, Kulldorff M, Platt R. Risk of misleading ventilator-associated pneumonia rates with use of standard clinical and microbiological criteria. Clin Infect Dis. 2008;46:1443-1446. https://doi.org/10.1086/587103

7. Lisboa T, Rello J. Diagnosis of ventilator-associated pneumonia: is there a gold standard and a simple approach? Curr Opin Infect Dis. 2008;21:174-178. https://doi.org/10.1097/qco.0b013e3282f55dd1

8. Tejerina E, Esteban A, Fernandez-Segoviano P, et al. Accuracy of clinical definitions of ventilator- associated pneumonia: comparison with autopsy findings. J Crit Care. 2010;25:62-68. https://doi.org/10.1016/j.jcrc.2009.05.008

9. Schurink CA, Van Nieuwenhoven CA, Jacobs JA, et al. Clinical pulmonary infection score for ventilator- associated pneumonia: accuracy and inter-observer variability. Intensive Care Med. 2004;30:217-224. https://doi.org/10.1007/s00134-003-2018-2

10. A randomized trial of diagnostic techniques for ventilator-associated pneumonia. N Engl J Med. 2006;355:2619-2630.

11. Calandra T, Cohen J. The international sepsis forum consensus conference on definitions of infection in the intensive care unit. Crit Care Med. 2005;33:1538-1548. https://doi.org/10.1097/01.ccm.0000168253.91200.83

12. Horan TC, Andrus M, Dudeck MA. CDC/NHSN surveillance definition of health care-associated infection and criteria for specific types of infections in the acute care setting. Am J Infect Control. 2008;36:309-332. https://doi.org/10.1016/j.ajic.2008.03.002

13. Minei JP, Hawkins K, Moody B, et al. Alternative case definitions of ventilator-associated pneumonia identify different patients in a surgical intensive care unit. Shock. 2000;14:331-336; discussion 336-337. https://doi.org/10.1097/00024382-200014030-00016

14. Dellinger RP, Levy MM, Carlet JM, et al. Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock: 2008. Crit Care Med. 2008;36:296-327. https://doi.org/10.1007/s00134-008-1090-z

15. Pugin J, Auckenthaler R, Mili N, Janssens JP, Lew PD, Suter PM. Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid. Am Rev Respir Dis. 1991;143:1121-1129. https://doi.org/10.1164/ajrccm/143.5_pt_1.1121

16. Cohen JA. Coefficient of Agreement for Nominal Scales. Educ Psychol Meas. 1960;20:37-46. https://doi.org/10.1177/001316446002000104

17. Rubenfeld GD, Caldwell E, Granton J, Hudson LD, Matthay MA. Interobserver variability in applying a radiographic definition for ARDS. Chest. 1999;116:1347-1353. https://doi.org/10.1378/chest.116.5.1347

18. Meade MO, Cook RJ, Guyatt GH, et al. Interobserver variation in interpreting chest radiographs for the diagnosis of acute respiratory distress syndrome. Am J Respir Crit Care Med. 2000;161:85-90. https://doi.org/10.1164/ajrccm.161.1.9809003

19. Thomas BW, Maxwell RA, Dart BW, et al. Errors in administrative-reported ventilator-associated pneumonia rates: are never events really so? Am Surg. 2011;77:998-1002.

20. Klompas M. Interobserver variability in ventilator-associated pneumonia surveillance. Am J Infect Control. 2010;38:237-239. https://doi.org/10.1016/j.ajic.2009.10.003

21. Magill SS, Klompas M, Balk R, et al. Developing a new, national approach to surveillance for ventilator- associated events: executive summary. Chest. 2013;144:1448-1452. https://doi.org/10.1086/673463

22. Seferian EG, Afessa B. Demographic and clinical variation of adult intensive care unit utilization from a geographically defined population. Crit Care Med. 2006;34:2113-2119. https://doi.org/10.1097/01.ccm.0000227652.08185.a4

23. Singh B, Hanson AC, Alhurani R, et al. Trends in the incidence and outcomes of disseminated intravascular coagulation in critically ill patients (2004-2010): a population-based study. Chest. 2013;143:1235-1242. https://doi.org/10.1378/chest.12-2112

24. St Sauver JL, Grossardt BR, Leibson CL, Yawn BP, Melton LJ, 3rd, Rocca WA. Generalizability of epidemiological findings and public health decisions: an illustration from the Rochester Epidemiology Project. Mayo Clin Proc. 2012;87:151-160. https://doi.org/10.1016/j.mayocp.2011.11.009