Skip to main content Accessibility help

Development of an Algorithm for Surveillance of Ventilator-Associated Pneumonia With Electronic Data and Comparison of Algorithm Results With Clinician Diagnoses

  • Michael Klompas (a1) (a2) (a3), Ken Kleinman (a1) (a2) and Richard Platt (a1) (a2) (a3)



Surveillance for ventilator-associated pneumonia (VAP) using standard Centers for Disease Control and Prevention (CDC) criteria is labor intensive and involves many subjective assessments. We sought to improve the efficiency and objectivity of VAP surveillance by adapting the CDC criteria to make them amenable to evaluation with electronic data.


Prospective comparison of the accuracy of VAP surveillance by use of an algorithm with responses to prospective queries made to intensive care physicians. CDC criteria for VAP were used as a reference standard to evaluate the algorithm and clinicians' reports.


Three surgical intensive care units and 2 medical intensive care units at an academic hospital.


A total of 459 consecutive patients who received mechanical ventilation for a total of 2,540 days underwent surveillance by both methods during consecutive 3-month periods. Electronic surveillance criteria were chosen to mirror the CDC definition. Quantitative thresholds were substituted for qualitative criteria. Purely subjective criteria were eliminated. Increases in ventilator-control settings were taken to indicate worsening oxygenation. Semiquantitative Gram stain of pulmonary secretion samples was used to assess whether there was sputum purulence.


The algorithm applied to electronic data detected 20 patients with possible VAP. All cases of VAP were confirmed in accordance with standard CDC criteria (100% positive predictive value). Prospective survey of clinicians detected 33 patients with possible VAP. Seventeen of the 33 possible cases were confirmed (52% positive predictive value). Overall, 21 cases of confirmed VAP were identified by either method. The algorithm identified 20 (95%) of 21 known cases, whereas the survey of clinicians identified 17 (81%) of 21 cases.


Surveillance for VAP using electronic data is feasible and has high positive predictive value for cases that meet CDC criteria. Further validation of this method is warranted.


Corresponding author

Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Healthcare, 133 Brookline Ave., 6th Floor, Boston, MA (


Hide All
1.Cardo, DM, Brennan, PJ, Peaden, D Jr.Mandatory reporting of hospital-acquired infections: steps for success. J Law Med Ethics 2005;33:8688.
2.Berwick, DM, Calkins, DR, McCannon, CJ, Hackbarth, AD. The 100,000 lives campaign: setting a goal and a deadline for improving health care quality. JAMA 2006;295:324327.
3.Horan, T, Gaynes, R. Surveillance of nosocomial infections. In: Mayhall, C, ed. Hospital Epidemiology and Infection Control. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 2004:16591702.
4.Fabregas, N, Ewig, S, Torres, A, et al.Clinical diagnosis of ventilator associated pneumonia revisited: comparative validation using immediate post-mortem lung biopsies. Thorax 1999;54:867873.
5.Bregeon, F, Papazian, L, Thomas, P, et al.Diagnostic accuracy of protected catheter sampling in ventilator-associated bacterial pneumonia. Eur Respir J 2000;16:969975.
6.Torres, A, el-Ebiary, M, Padro, L, et al.Validation of different techniques for the diagnosis of ventilator-associated pneumonia: comparison with immediate postmortem pulmonary biopsy. Am J Respir Crit Care Med 1994;149:324331.
7.Wunderink, RG, Woldenberg, LS, Zeiss, J, Day, CM, Ciemins, J, Lacher, DA. The radiologic diagnosis of autopsy-proven ventilator-associated pneumonia. Chest 1992;101:458463.
8.Hawkins, DM, Garrett, JA, Stephenson, B. Some issues in resolution of diagnostic tests using an imperfect gold standard. Stat Med 2001;20:19872001.
9.Centers for Disease Control and Prevention. National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2004, issued October 2004. Am J Infect Control 2004;32:470485.
10.Andrews, CP, Coalson, JJ, Smith, JD, Johanson, WG Jr.Diagnosis of nosocomial bacterial pneumonia in acute, diffuse lung injury. Chest 1981;80:254258.
11.Fagon, JY, Chastre, J, Hance, AJ, Domart, Y, Trouillet, JL, Gibert, C. Evaluation of clinical judgment in the identification and treatment of nosocomial pneumonia in ventilated patients. Chest 1993;103:547553.
12.Maclntyre, NR, Cook, DJ, Ely, EW Jr, et al.Evidence-based guidelines for weaning and discontinuing ventilatory support: a collective task force facilitated by the American College of Chest Physicians; the American Association for Respiratory Care; and the American College of Critical Care Medicine. Chest 2001;120:375S395S.
13.Safdar, N, Dezfulian, C, Collard, HR, Saint, S. Clinical and economic consequences of ventilator-associated pneumonia: a systematic review. Crif Care Med 2005;33:21842193.
14.Klompas, M. Does this patient have ventilator-associated pneumonia? JAMA 2007;297:15831593.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed