Impact of inappropriate empiric antimicrobial therapy on outcomes in Gram-negative infections

Treating gram-negative infections continues to be a significant challenge in the era of antimicrobial resistance. Gram-negative pathogens are common causes of a variety of infections, which impacts the choice of empiric antimicrobial therapy. In addition to infection type, underlying resistance patterns also impact empiric therapeutic choices. The impact of IEAT on morbidity on Gram-negative bacteremia and sepsis is fairly well characterized. However, the impact of IEAT on morbidity and mortality is not well understood across the spectrum of infections. Both multi-drug resistance (MDR) and inappropriate antimicrobial therapy have been associated with increased hospital cost; however, due to the incidence of IEAT associated with MDR infections, it is not clear whether increased costs can be attributed to the antimicrobial resistance or IEAT. Small populations in previous studies limit this type of analysis, which may explain why the separation of these effects has not been observed. This proposal aims to analyze all Gram-negative infections in a five-year period to assess outcomes between IEAT and appropriate empiric therapy exposure. Aim 1: To assess the incidence of inappropriate empiric antimicrobial therapy (IEAT) for Gram-negative infections and the impact of IEAT on morbidity and mortality in adult patients with a variety of Gram-negative infections. Aim 2: To assess the impact of multidrug resistant organisms and IEAT on length of stay and hospital costs compared to patients with susceptible organisms and IEAT. Aim 3: Characterize risk factors for specific MDR organisms and develop a clinical scoring system to drive empiric therapy in patients at risk for MDR organisms. Hypothesis: Multidrug resistance (MDR) and IEAT both independently increase morbidity, mortality, length of stay, and hospital costs.