A model to predict mortality following Pseudomonas aeruginosa bacteremia

Infections caused by Pseudomonas aeruginosa are associated with significant mortality. Existing mathematical models identifying mortality risk factors lack validation. We developed and validated a model to predict mortality in patients with P. aeruginosa bacteremia. Risk factors for 30-day mortality were examined through multivariate logistic regression in 114 patients. Independent predictors of mortality included isolation of a multidrug-resistant strain, APACHE II ≥23, and age ≥65 years. Clonality was assessed for multidrug-resistant isolates. Predicted probability of 30-day mortality was validated in 49 patients, after conditioning the model by the identified risk factors. The patients were split into 'high-risk' and 'low-risk' groups based on model-predicted mortality; the observed/expected ratios were 1.21 and 1.92, respectively. Our model was reasonable in predicting 30-day mortality in patients with P. aeruginosa bacteremia. Our results may be useful for developing strategies to reduce mortality attributed to P. aeruginosa.