Rapid diagnostic tests and antimicrobial stewardship programs for the management of bloodstream infection: What is their relative contribution to improving clinical outcomes? A systematic review and network meta-analysis

Background: Evidence about the clinical impact of rapid diagnostic tests (RDT) for the diagnosis of bloodstream infections is limited, and whether RDT are superior to conventional blood cultures (BC) embedded within antimicrobial stewardship programs (ASP) is unknown.

Methods: We performed network meta-analyses (NMA) using results from studies of patients with bloodstream infection with the aim of comparing the clinical impact of RDT (applied on positive BC broth or whole blood) to conventional BC, both assessed with and without ASP with respect to mortality, length of stay (LOS) and time to optimal therapy (TOT).

Results: Eighty-eight papers were selected, including 25,682 patient encounters. There was an appreciable amount of statistical heterogeneity within each meta-analysis. The NMA showed a significant reduction in mortality associated with the use of RDT + ASP vs BC alone (OR 0.72, 95%CI 0.59, 0.87) and with the use of RDT + ASP vs BC + ASP (OR 0.78 95%CI 0.63, 0.96). No benefit in survival was found associated with the use of RDT alone nor with BC + ASP compared to BC alone. A reduction in LOS was associated with RDT + ASP vs BC alone (0.91, 95%CI 0.84, 0.98) while no difference in LOS was shown between any other groups. A reduced TOT was shown when RDT + ASP was compared to BC alone (-29 h, 95%CI -35, -23), BC + ASP (-18 h, 95%CI -27, -10) and to RDT alone (-12 h, 95%CI -20, -3).

Conclusion: The use of RDT + ASP may lead to a survival benefit even when introduced in settings already adopting effective ASP in association with conventional BC.