Hospital economic impact of an outbreak of Pseudomonas aeruginosa infections.

A total of 67 patients involved in an outbreak of Pseudomonas aeruginosa in the intensive care unit (ICU) were retrospectively followed to determine whether case patients experienced differences in cost, length of stay and survival rates when compared with non-affected patients. The method of microcosting, a technique that involves detailed identification and measurement of all care items and services offered by the hospital, was used to identify attributable costs related to diagnostic procedures, pharmacy and ICU stay of each patient. Seventeen patients developed nosocomial P. aeruginosa infection. On average, these patients incurred adjusted hospital costs of euro 27,917, 66% higher than non-case patients (P=0.002). The extra length of ICU stay attributable to P. aeruginosa infection was 70 days (P=0.0001). In multiple linear regression analysis, we found that P. aeruginosa infection was an independent predictor of increased hospital costs and length of hospital stay. On the basis of these findings, a conservative estimate of the extra cost attributable to P. aeruginosa infection in our ICU was euro 312,936 (95% confidence interval: 305,676-320,196).