Methods.

Participating centers included 7 intensive care units in France with a total of 140 beds. Criteria for inclusion were age18 years or older, suspected infection, and no antibiotic within 24 hours. Participants were randomly assigned 1:1 to procalcitonin monitoring or control group (standard clinical care). The use of antibiotics in the procalcitonin group was:

• Start antibiotics with a threshold procalcitonin level ≥ 0.5 µg/L;
• Stop antibiotics with a procalcitonin level <>
• Continue antibiotics with a reduction of <>
• Change antibiotics with an increase in the procalcitonin level.

The control group received antibiotics according to "standard practice."