Methods: This single-center, pre-post quasi-experimental study evaluated hospitalized patients with positive blood cultures identified via MALDI-TOF combined with prospective AMS intervention (November 2015-January 2016) compared to a control cohort with MALDI-TOF identification and no active AMS intervention (November 2014-January 2015). AMS intervention included: comprehensive blood culture guideline development, real-time MALDI-TOF pharmacist notification, and prospective AMS provider feedback. The primary outcome was time to optimal antimicrobial therapy (TTOT).
Results: A total of 252 blood cultures were included in the final analysis: 126 in each group. MALDI-TOF + AMS intervention significantly reduced overall TTOT (75.2 vs 43.1 h, p <0.001), Gram + contaminant TTOT (48.2 vs 11.8 h, p <0.001), Gram - infection (GNI) TTOT (71.8 vs 35.9 h, p <0.001), improved Gram + infection (GPI) TTOT (64.0 vs 41.6 h, p 0.082), and reduced overall hospital LOS (15.0 vs 9.0 days, p 0.021). For GPI: reduced hospital LOS (14.6 vs 10.3 days, p 0.002) and length of antimicrobial therapy 24.3 vs 18.9 days, p 0.018). For GNI: reduced time to microbiologic clearance (51.1 vs 34.5 h, p <0.001), hospital LOS (15.4 vs 7.9 days, p 0.027), and ICU LOS (5.5 vs 1.2 days, p 0.035).
Conclusion: In order to achieve optimal outcomes, rapid identification with MALDI-TOF alone is not as impactful as MALDI-TOF combined with real-time AMS interventions.