Diagnostic performances of a combination of biomarkers
Biological3 ml of blood will be drawn at inclusion at the same time of the venipuncture prescribed for standard care. The dosage of the 7 biomarkers will be performed in a central laboratory. The adjudication committee will classify patients in 6 groups, based on their clinical data. The committee will not be aware of the biological results. The analysis of Train Set data will aim to identify the most effective combination of markers in response to the primary objective of identifying biomarkers for the diagnosis of severe bacterial infections. The best combination selected will then be applied to the Test Set data (approximately the other half of patients), in order to obtain its real and unbiased performance.
The calculation of positive and negative likelihood ratios will be performed.
The targeted performances are:
- A positive likelihood ratio (LR +) of 5.67 minimum, ideally greater than 8.5.
- A negative likelihood ratio (LR-) of 0.5 maximum, ideally less than 0.3.