Impact of intensive-care-unit (ICU)-acquired ventilator-associated pneumonia (VAP) on hospital mortality : a matched-paired case-control study

The effect of ICU-acquired ventilator-associated pneumonia (VAP) on hospital mortality is still a controversial issue in many countries. The aim of this study was to evaluate the effect of ICU-acquired VAP on hospital mortality in a Japanese university hospital. Our study population was comprised of patients aged 16 years or older who were admitted to our ICU and received mechanical ventilation for more than 48 hours during a period of 42 months as of December 2003. To evaluate whether VAP was an independent risk factor for hospital mortality after controlling for other clinical factors, patients with fatal outcomes (cases) were compared to those who survived (controls). From 587 eligible patients, we analyzed 75 cases and 150 controls who were successfully matched on sex, age, and the Acute Physiology and Chronic Health Evaluation II (APACHE II) score using conditional logistic regression models. Univariate analysis demonstrated that hemodialysis (odds ratio [OR], 2.24; 95% confi dence interval [CI], 1.21–4.15; p=0.01), surgical site infection (OR, 2.45; 95% CI, 1.22–4.91; p=0.01), and VAP (OR, 2.69; 95% CI, 1.55–4.69; p<0.001) were signifi cantly associated with hospital mortality. After adjusting for confounding factors, multivariate conditional logistic regression analysis showed that hemodialysis (OR, 2.05; 95% CI, 1.06–3.94; p=0.03) and VAP (OR, 2.20; 95% CI, 1.10–4.39; p=0.03) were independently associated with hospital mortality. In conclusion, these data suggest that ICU-acquired VAP signifi cantly affects hospital mortality.