Clinical Outcomes with Implementation of Accelerate Pheno™ Blood Culture Detection System for Gram-Negative Bacteremia

Delayed treatment in bacteremia increases patient morbidity and healthcare costs. Accelerate Pheno™ Blood Culture Detection System (AXDX) is a novel diagnostic technology for the rapid detection of gram-negative bacteremia. Studies have shown accurate and faster time to speciation and sensitivity (TTSS) by AXDX compared to conventional modality. However, however, our study further examined the direct impact of AXDX on clinical outcomes and cost. Our retrospective study consisted of 178 patients at least 18 years old admitted to our academic medical institution with gram-negative bacteremia. The pre-AXDX group had 91 patients admitted in 2019 while the post-AXDX group had 87 patients admitted in 2021. Demographics, microbes, TTSS, time to de-escalation of therapy (TTDeT), length of stay (LOS), readmissions, and Clostridioides difficile infection (CDI) rates were recorded and differences between the cohorts were statistically analyzed. The pre-AXDX group had 51.32% females, mean age of 60.28 years, mean Charlson Co-morbidity Index (CCMI) of 2.23, mean LOS of 21.19 days, and mean Pitt-Bacteremia Score (PBS) of 2.35. The post-AXDX group had 51.92% females, mean age of 63.66 years, mean CCMI of 2.99, median LOS of 15.02 days, and mean PBS of 2.71. Both groups’ top two sources of bacteremia were urinary and gastrointestinal and the two most common microbes were Escherichia coli and Klebsiella pneumoniae. Pre-AXDX's mean TTSS was 70.95 hours and 62.92 hours for post-AXDX. Pre-AXDX's mean TTDeT was 73.90 hours and 43.85 hours for post-AXDX. The pre-AXDX cohort had 7.12% increase in related readmissions, 5.45% more CDI, and 0.26% increase in inpatient mortality. In addition to faster TTSS with AXDX as seen with previous studies, our study shows clinical advantages with AXDX use. While both groups were comparable in bacteremia sources and microbes. The post-AXDX group had higher CCMI and PBS scores, indicating they were more ill. Despite this, the pre-AXDX group had longer TTDeT by 30.05 hours, longer mean LOS by 6.17 days, 5.45% more CDI, 7.12% more readmissions, and 0.26% more mortality rates. The pre-AXDX group also reported adverse reactions to antibiotics while the post-AXDX had none. Our data shows AXDX use improves clinical outcomes with fewer adverse effects, mortality, and CDI rates and decreases cost with shorter LOS and lower readmission rates.