Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2008;12(2):R44.
doi: 10.1186/cc6852. Epub 2008 Apr 2.

Risk factors for the development of nosocomial pneumonia and mortality on intensive care units: application of competing risks models

Martin Wolkewitz  1 , Ralf Peter Vonberg, Hajo Grundmann, Jan Beyersmann, Petra Gastmeier, Sina Bärwolff, Christine Geffers, Michael Behnke, Henning Rüden, Martin Schumacher
Affiliations
Comparative Study

Risk factors for the development of nosocomial pneumonia and mortality on intensive care units: application of competing risks models

Martin Wolkewitz et al. Crit Care. 2008.

Abstract

Introduction: Pneumonia is a very common nosocomial infection in intensive care units (ICUs). Many studies have investigated risk factors for the development of infection and its consequences. However, the evaluation in most of theses studies disregards the fact that there are additional competing events, such as discharge or death.

Methods: A prospective cohort study was conducted over 18 months in five intensive care units at one university hospital. All patients that were admitted for at least 2 days were included, and surveillance of nosocomial pneumonia was conducted. Various potential risk factors (baseline- and time-dependent) were evaluated in two competing risks models: the acquisition of nosocomial pneumonia and discharge (dead or alive; model 1) and for the risk of death in the ICU and discharge alive (model 2).

Results: Patients from 1,876 admissions were included. A total of 158 patients developed nosocomial pneumonia. The main risk factors for nosocomial pneumonia in the multivariate analysis in model 1 were: elective surgery (cause-specific hazard ratio = 1.95; 95% CI 1.33 to 2.85) or emergency surgery (1.59; 95% CI 1.10 to 2.28) prior to ICU admission, usage of a nasogastric tube (3.04; 95% CI 1.25 to 7.37) and mechanical ventilation (5.90; 95% CI 2.47 to 14.09). Nosocomial pneumonia prolonged the length of ICU stay but was not directly associated with a fatal outcome (p = 0.55).

Conclusion: More studies using competing risk models, which provide more accurate data compared to naive survival curves or logistic models, should be carried out to verify the impact of risk factors and patient characteristics for the acquisition of nosocomial infections and infection-associated mortality.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Competing endpoints in model 1 and model 2.
Figure 2
Figure 2
Cumulative incidence function for nosocomial pneumonia and discharge (dead or alive) (model 1). (a) In the two upper figures the risk factor 'elective surgery' is considered. (b) In the two lower figures the risk factor 'pneumonia on admission' is considered.
Figure 3
Figure 3
Cumulative incidence function for death and discharge (model 2). (a) In the two upper figures the risk factor 'elective surgery' is considered. (b) In the two lower figures the risk factor 'pneumonia on admission' is considered.
See this image and copyright information in PMC

Comment in

References

    1. Cook DJ, Walter SD, Cook RJ, Griffith LE, Guyatt GH, Leasa D, Jaeschke RZ, Brun-Buisson C. Incidence of and risk factors for ventilator-associated pneumonia in critically ill patients. Ann Intern Med. 1998;129:433–440. - PubMed
    1. Safdar N, Dezfulian C, Collard HR, Saint S. Clinical and economic consequences of ventilator-associated pneumonia: a systematic review. Crit Care Med. 2005;33:2184–2193. doi: 10.1097/01.CCM.0000181731.53912.D9. - DOI - PubMed
    1. Meric M, Willke A, Caglayan C, Toker K. Intensive care unit-acquired infections: incidence, risk factors and associated mortality in a Turkish university hospital. Jpn J Infect Dis. 2005;58:297–302. - PubMed
    1. Apostolopoulou E, Bakakos P, Katostaras T, Gregorakos L. Incidence and risk factors for ventilator-associated pneumonia in 4 multidisciplinary intensive care units in Athens, Greece. Respir Care. 2003;48:681–688. - PubMed
    1. Putter H, Fiocco M, Geskus RB. Tutorial in biostatistics: competing risks and multi-state models. Stat Med. 2007;26:2389–2430. doi: 10.1002/sim.2712. - DOI - PubMed

Publication types

LinkOut - more resources