RESUMO
OBJECTIVE: Nosocomial infection causes a prolonged hospital stay and an increase in care costs. The objective of this study was to determine the length of stay excess and costs attributable to nosocomial bacteremia. PATIENTS AND METHODS: Retrospective study of clinical records of 148 patients with nosocomial bacteremia during 1996. A matched case-control study was performed. For matching, the following parameters were used: RDG, year of admission, age 10 years, main diagnosis and number of secondary diagnoses. Costs were determined by excess length of hospital stay and calculating alternative costs. RESULTS: Matching was obtained for 100 cases (67.5%) and cost estimation was performed. Compared with cases, non-matched cases showed differences regarding significant issues for cost, such as hospital stay ( p = 0.01), number of empirical (p = 0.001) or definitive antibiotics (p = 0.03). The median hospital stay for cases was longer than for controls (35 vs 15.5 days, respectively; p = 0.000). When only survivor case-control pairs were considered (n = 75), cases remained in hospital for a median of 36 vs 15 days for controls (p = 0.000). Hospital stay days attributable to nosocomial bacteremia were 19.5 for all matched and 21 for matched survivor cases. Only 76% of cases had stay days attributable to bacteremia. Significant differences between cases and controls included: the mean total costs of admission (p = 0.000), cost of stay (p = 0.001), pharmaceutical expenses (p = 0.000), and cost of microbiological studies (p = 0.000), laboratory work-up (p = 0.001) and radiological studies (p = 0.000). Hospital stay represented more than 60% of costs, followed by pharmaceutical expenses. Cost differences between bacteremic patients and controls, calculated in function of stay median, was 4.424 euros (p = 0.000) and 4.744 euros (p = 0.000) for alternative costs. Ten cases showed a difference that represented more than half of the total difference. CONCLUSIONS: Nosocomial bacteremia represent a stay prolongation and a significant economical burden. Hospital stay and pharmaceutical expenses accounted for the most part of the associated costs. The differences in costs obtained with both methods were small. Since not all selected cases were matched, there may be an error in the appreciation of the difference between cases and controls.