Estimating the costs associated with nosocomial urinary tract infection.: A case-control study

Background. Nosocomial infection (NI) is associated with increased resource use. The current study addressed the cost excess attributable to nosocomial urinary tract infection (NUTI). Methods. Case-control study conducted in a cohort population. For matching, the Diagnostic Related Group (DRG) to which the episode of case patient was ascribed was used. Then, a further search was conducted in the hospital discharge database with the following parameters: DRG, gender, age, admission date, department, comparison of length of stays, main diagnosis, co-morbidities, number of secondary diagnoses and procedures. Matching was achieved for 64 episodes (71%), and upon them an estimation of costs was performed. Results. The mean length of stay for cases were 15.3 (median: 12) and 12.3 (median: 11) days for cases and controls, respectively (p = 0.0001). The excess of length of stay attributable to NUTI was 3 days (95% Cl 1.6-4.7), longer for patients admitted to Medical Departments (5.3 days) than for patients admitted to Surgical Departments (2 days) (p = 0,03). The use of diagnostic resources was significantly higher for bacteriological testing only. The use of antibiotics and fluid therapy was higher among infected patients. Out of the total excess of the estimated costs per episode, 132,047 ptas, 93% corresponded to the increase in hospital stay. Ten patients (15.6%) were responsible for 68% of the total of extra-costs. In 17 occasions (26.6%), the control patient used more resources than the infected patient. Conclusions. Nosocomial urinary tract infection is associated with a resource use directly related to its presence. For the most part, it is related to the prolongation of hospital stay.