Trial Domains

The vanguard phase included five active domains with open-label 1:1 randomisation. The catheter domain compared central venous catheter replacement within 72 hours of susceptibility results with retention until no longer clinically needed. The oral transition domain compared oral beta-lactams with non-beta-lactam agents. The de-escalation domain compared continued empiric Gram negative antibiotic treatment with switching to narrower-spectrum therapy after susceptibility results. The low-risk AmpC domain compared ceftriaxone with carbapenems for Serratia, Morganella, and Providencia bloodstream infections. The follow-up blood culture domain compared routine blood culture at 4 ± 1 days with cultures only when clinically indicated.