Clinical Impact of the BIOFIRE® FILMARRAY® Pneumonia Panel in the Veterans Affairs Healthcare System: A Difference-in-Differences Study

Abstract Background Rapid diagnostics such as the BIOFIRE® FILMARRAY® Pneumonia (PN) Panel may enhance antibiotic optimization, yet real-world evidence remains limited, and few studies have assessed how differences in institutional antimicrobial stewardship (ASP) capacity influence clinical outcomes. Methods We conducted a national, multicenter retrospective study of ICU patients with pneumonia admitted to Veterans Health Administration hospitals. Hospitals that implemented the PN Panel for ≥6 months served as intervention sites, while matched facilities without implementation served as controls. Outcomes were assessed using a difference-in-differences framework with inverse probability weighting to account for baseline imbalances and secular trends, including those related to the COVID-19 pandemic. Co-primary outcomes, assessed following index culture collection, were early antimicrobial de-escalation (24–48 hours) and early appropriate therapy (0–24 hours); secondary outcomes were 30-day and ICU mortality. Results The study included 11 746 patients, including 4523 from hospitals that implemented the BIOFIRE® PN Panel and 7223 from matched control hospitals. Overall, PN implementation was associated with early antimicrobial de-escalation (adjusted RR [aRR], 1.14; 95% CI, 1.04–1.26). Among culture-positive patients, PN Panel implementation was significantly associated with early antimicrobial de-escalation (aRR, 1.23; 95% CI, 1.02–1.50) and early appropriate therapy (aRR, 1.11; 95% CI, 1.04–1.18). Overall ICU and 30-day mortality did not differ, though ICU mortality among culture-positive patients was relatively lower following PN Panel implementation (aRR, .70; 95% CI, 0.50–0.97). Improvements in antimicrobial optimization were most evident in hospitals with greater ASP capacity. Conclusions BIOFIRE® PN Panel implementation improved antibiotic optimization in critically ill pneumonia patients, with the greatest gains seen in hospitals with comprehensive ASP programs.