LAUSR

Abstract Background Bloodstream infections are a major cause of morbidity and mortality worldwide, with favorable clinical outcomes associated with early optimal antibiotic selection. Rapid diagnostics have become a key part in achieving this. Biofire Filmarray® was introduced at our institution for rapid blood culture (BC) identification, coupled with antimicrobial stewardship (AS) interventions. We aimed to assess the impact of this test on time to adequate antimicrobial therapy in a setting with pre-existing effective AS interventions. Methods An observational retrospective chart review, pre and post study was performed. We reviewed adult positive BC before and after implementation of Biofire. Outcomes were: (1) time from BC result reported to health care provider to start of adequate antimicrobial therapy,(2) time to stopping antimicrobial therapy in BC thought to be contaminants, (3) time to any change in antimicrobial therapy and (4) a composite outcome of outcomes 1 and 2. A univariate Cox proportional hazards model was performed. Results 326 positive BC were analyzed, 173 before and 153 after Biofire implementation. At the time of healthcare provider notification, 77 were not on adequate antimicrobials, with median time to adequate therapy of 6.98 hours. (IQR 3.93–23.96) before and 6.1 hours. (IQR 1.84–20.95) after implementation, P = 0.48. There were 75 BC classified as contaminants and median time to stopping antimicrobials was 48.28 (IQR 18.56–89.36) vs. 45.25 hours. (IQR 15.12–100.60), P = 0.61. Time to any change in any antimicrobial therapy was similar with a median of 13.05 (IQR 4.00–36.77) vs. 10.90 hours. (IQR 2.97–31.10), P = 0.87. Analysis of the composite outcome revealed a median of 23.95 (6.29–58.50) vs. 14.82 (IQR 4.07–44.79) hours. (Hazard ratio 1.33, 95% confidence interval 0.96–1.84, P = 0.09). Conclusion Implementation of the Biofire Filmarray® did not have a statistically significant effect on our composite outcome of time to adequate therapy and time to discontinuation in the case of contaminants. Our findings suggests that when added to other effective AS surveillance and interventions, the magnitude of the clinical impact of rapid PCR diagnostics for BC identification is minimal. Disclosures D. R. Snydman, Merck: Scientific Advisor, Consulting fee; Shire: Scientific Advisor, Consulting fee