Antimicrobial Stewardship for Enterobacterales Bacteremia Management

A Cluster-randomized Controlled Pragmatic Trial to Evaluate Antimicrobial Stewardship Strategies for Short-course and Oral-switch Antibiotic Therapy for Bloodstream Infections Due to Enterobacterales

We hypothesize that a multifaceted antibiotic stewardship intervention incorporating physician education, prospective chart review with antibiotic recommendation, and provision of follow-up by a multidisciplinary antibiotic stewardship team, is more effective than physician education and reminders alone in improving physicians' prescription of short-course and oral-switch antibiotic therapy for patients with bloodstream infections due to Enterobacterales (BSI-E).

This study is to:

1. determine the effectiveness of a multifaceted antibiotic stewardship intervention in improving physicians' prescription of short-course antibiotic therapy for BSI-E
2. determine the effectiveness of a multifaceted antibiotic stewardship intervention in improving physicians' de-escalation to oral antibiotic therapy for BSI-E

Antimicrobial resistance is a major global threat, causing 5 million deaths globally in 2019. One of the crucial strategies to control the emergence and spread of multidrug-resistant organisms (MDRO) is to minimize unnecessary antibiotics exposure.

Shorter duration of antibiotic therapy and oral-switch therapy for bloodstream infection due to Enterobacterales (BSI-E) had demonstrated similar treatment success and clinical outcomes as compared with longer courses in randomized controlled trials. Despite the release of such data, clinicians may be reluctant to shortern duration of therapy for BSI-E and adopt oral-switch approach.

This study aims to determine the optimal approach to aid clinicians in adopting evidence-based practice in a clinical setting. This study is a pragmatic cluster-randomized controlled trial in the medical wards of an acute hospital. A cluster, as the unit of randomization, is a medical ward. Medical wards will be randomized to three groups: (1) physician education only; (2) physician education and paper reminder; (3) multifaceted antibiotic stewardship intervention. The prescription of antibiotic therapy by treating physicians and outcomes of patients with BSI-E will be studied.

Patients' antibiotics regimen and clinical outcomes in the three groups will be compared.

Inclusion Criteria:

• aged ≥18 years;
• hospitalization in one of the medical wards of the hospital; and
• isolation of Enterobacterales in at least one blood culture bottle, where Enterobacterales include Escherichia coli, Klebsiella, Proteus, Enterobacter, Serratia, Citrobacter, Providencia and Morganella species.

Exclusion Criteria:

• concomitant isolation of pathogens other than Enterobacterales in blood or other relevant clinical specimens;
• infections requiring prolonged courses of antibiotics, such as intra-abdominal abscess, central nervous system infection, endocarditis, lung abscess or empyema, osteomyelitis, and prostatitis;
• focus of infection not controlled;
• nosocomial infection with onset within 7 days; or
• Presence of neutropenia, allogenic stem cell transplant within one year, use of high-dose steroid (>40mg prednisolone or equivalent for > 2 weeks), or
• died before day 7 will be excluded from the analysis, or
• already on more than 7 days of antibiotics for BSI-E at the time of screening.