Biomarker Signature-Supported Antibiotic Treatment Decisions in ICU

This study will pragmatically combine the evaluation of a diagnostic test with an antibiotic treatment decision matrix, in a manner that mimics real-life but is as close as possible to a "best-case" scenario.

Primary objective is to evaluate the combined endpoint of efficacy and safety at 28 days (approximately 4 weeks). This will include:

• Efficacy: Assessed by the use of antibiotics.
• Safety: Assessed by clinical outcomes.

Eligible participants will be randomized 1:1 to either the intervention or control groups. Evaluation of safety and efficacy will be combined to provide a global evaluation of the benefits and risks of the intervention, using the Desirability of Outcome Ranking (DOOR) further combined with Response Adjusted for Duration of Antibiotic Risk (RADAR).

The hypothesis is that participants in the intervention group will have lower antibiotic exposure, without increased harm (worse clinical outcomes related to infection or significant adverse events) .

Inclusion criteria

• Admitted to the Intensive Care Unit (ICU)
• Started on antibiotics for any suspected or confirmed infection in the preceding 72 hours (about 3 days)
• Treating doctor(s) willing to consider BV test result in antibiotic treatment decision making

Exclusion criteria

• Severe immunocompromise/immunosuppression

• Congenital immunodeficiency
• HIV with CD4 < 20
• Active chemotherapy and profound neutropenia (ANC < 100) expected to last > 7 days;
• solid organ or stem cell transplant within preceding 6 months AND active GVHD
• Receiving high dose steroids (Pred > 20mg/day for > or = 2 weeks)
• Advanced metastatic cancer irrespective of treatment
• Palliative intent, death imminent and inevitable within 4 weeks
• Antibiotic to be discontinued within 24h (ex. Prophylaxis)
• Active infection diagnosed and treated with antibiotics within preceding 2 weeks
• Previously included during the same hospitalization