Predictors of recurrence, early treatment failure and death from Staphylococcus aureus bacteraemia: observational analyses within the ARREST trial

Abstract Objectives Adjunctive rifampicin did not reduce failure/recurrence/death as a composite endpoint in the ARREST trial of Staphylococcus aureus bacteraemia, but did reduce recurrences. We investigated clinically-defined 14-day treatment failure, and recurrence and S. aureus-attributed/unattributed mortality by 12-weeks to further define their predictors. Methods A post-hoc exploratory analysis using competing risks models was conducted to identify sub-groups which might benefit from rifampicin. A points-based recurrence risk score was developed and used to compare rifampicin's benefits. Results Recurrence was strongly associated with liver and renal failure, diabetes and immune-suppressive drugs (p Conclusions Rifampicin reduces recurrences overall; those with greatest absolute risk reductions were identified using a simple risk score. Source control and adequate duration of antibiotic therapy remain essential to prevent recurrence and improve outcomes.