[Costs associated with nosocomial bacteraemias in a University Hospital]

To describe the increase in costs due to patients who had any episode of nosocomial bacteraemia (NB) in a University Hospital, compared to the costs of patients with the same illness who did not.

Descriptive and retrospective study.

all hospitalisation episodes between January 2005 and December 2007. We compared the patients who suffered some episode of NB, with the patients who did not. Dependent variable: cost of the hospitalisation episode. Main explanatory variable: presence of nosocomial bacteraemia. A generalized linear model was adjusted, with Gamma distribution and link logarithm function, given the distribution of the costs.

There were 640 hospital episodes with NB and 28,459 with no NB. The average incremental cost for the hospitalisations with NB was 14,735.5€, adjusted for the disease. The impact on the costs for the hospital due to patients with NB was 9,430,713€. The most frequent source of infection was the catheter (35.5%), with an average increase in cost of 18,078€. In the multivariable model, the cost of patients with NB and involving a Gram(+) microorganism was 2.1 times more than that of patients without bacteraemia (95% CI; 1.96-2.23), if the microorganism was Gram(-) it was 1.8 times more (95% CI; 1.70-1.93), and for a fungus it was 2.4 time more (95% CI; 1.95-2.89).

This analysis shows the significant impact in the financial costs due to NB, and gives a measure of the cost-benefit of investing in resources to prevent them. Knowing the source cause of the bacteraemia allows priority to be given to these areas and to promote the necessary actions designed to prevent them.