Cost of Gram-negative resistance*

OBJECTIVE: It is unclear that infections with Gram-negative rods resistant to at least one major class of antibiotics (rGNR) have a greater effect on patient morbidity than infections caused by sensitive strains (sGNR). We wished to test the hypothesis that rGNR infections are associated with higher resource utilization. DESIGN: Retrospective observational cohort study of prospectively collected data. SETTING: University hospital surgical intensive care unit and ward. PATIENTS: Surgical patients with at least one GNR infection. MEASUREMENTS: We compared admissions treated for rGNR infection with those with sGNR infections. Primary outcomes were total hospital costs and hospital length of stay. Other outcomes included antibiotic treatment cost, in-hospital death, and intensive care unit length of stay. After univariate analysis comparing outcomes after rGNR infection with those after sGNR infection, multivariate linear regression models for hospital cost and length of stay were created to account for potential confounders. MAIN RESULTS: Cost data were available for 604 surgical admissions treated for at least one GNR infection (Centers for Disease Control and Prevention criteria), 137 (23%) of which were rGNR infections. Admissions with rGNR infections were associated with a higher severity of illness at the time of infection (Acute Physiology and Chronic Health Evaluation II score, 17. 6 +/- 0. 6 vs. 13. 9 +/- 0. 3), had higher median hospital costs (80, 500 vs. 29, 604, p <. 0001) and median antibiotic costs (2, 607 vs. 758, p <. 0001), and had longer median hospital length of stay (29 vs. 13 days, p <. 0001) and median intensive care unit length of stay (13 days vs. 1 day, p <. 0001). Infection with rGNR within the first 7 days of admission was independently predictive of increased hospital cost (incremental increase in median hospital cost estimated at 11, 075; 95% confidence interval, 3, 282-20, 099). CONCLUSIONS: Early infection with rGNR is associated with a high economic burden, which is in part related to increased antibiotic utilization compared with infection with sensitive organisms. Efforts to control overuse of antibiotics should be pursued.