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The VIDAS® TBI (GFAP, UCH-L1) test is composed of two automated assays - VIDAS® TBI (GFAP) and VIDAS® TBI (UCH-L1) - to be used on the VIDAS® 3 instrument for the quantitative measurement of Glial Fibrillary Acidic Protein (GFAP) and Ubiquitin C-terminal Hydrolase (UCH-L1) in human serum using the ELFA (Enzyme Linked Fluorescent Assay) technique. The results of both assays are requred to obtain an overall qualitative test interpretation.

The overall qualitative VIDAS® TBI (GFAP, UCH-L1) test result is used, in conjunction with clinical information, to aid in the evaluation of patients (18 years of age or older), presenting within 12 hours of suspected mild traumatic brain injury (Glasgow Coma Scale score 13-15), to assist in determining the need for a Computed Tomography (CT) scan of the head. A negative interpretation of VIDAS® TBI (GFAP, UCH-L1) test is associated with the absence of acute intracranial lesions visualized on a head CT scan.

The VIDAS® TBI (GFAP, UCH-L1) test is composed of two automated assays – VIDAS® TBI (GFAP) and VIDAS® TBI (UCH-L1) – to be used on the VIDAS® 3 instrument. Similar to other VIDAS assays, VIDAS TBI (GFAP) and VIDAS TBI (UCH-L1) test kits (specific to each biomarker) contain the solid phase receptacles (SPRs®), the reagent strips, Product Calibrator S1 and Product Control C1. These test kits will also contain the master lot entry (MLE) data i.e., a barcode printed on the outer label of the packaging, as well as the reference number of the package insert to download from the bioMérieux website.

Whether it be for the GFAP or UCH-L1 quantification, the test combines a three-step enzyme immunoassay sandwich method with a final fluorescent detection step, also known as enzyme-linked fluorescent assay (ELFA).

The Solid Phase Receptacle (SPR) serves as the solid phase as well as the pipetting device. The inner surface of the SPR is coated with antibodies aqainst the substance of interest i.e., anti-GFAP or anti-UCH-L1 antibodies. The reagent strip consists of 10 wells covered with a labeled foil seal. Well 1 is designated for the sample. Eight of the wells contain sample diluent, wash buffer, conjugate, and tracer. The last well contains the fluorescent substrate. All of the assay steps are performed automatically by the instrument.

The intensity of the fluorescence is proportional to the concentration of the analyte the sample. At the end of the assay, the biomarker concentration is automatically calculated by the instrument in relation to the calibration curve and stored in the Master Lot Entry (MLE) data.

VIDAS TBI (GFAP) and VIDAS TBI (UCH-L1) results are reported separately: the VIDAS 3 reports the calculated concentration and the qualitative interpretation for each. The final result i.e., the patient's status in relation to suspected mild traumatic brain injury, must be interpreted by the user according to the decision tree presented in the package insert.

This document describes the validation of the VIDAS® TBI (GFAP, UCH-L1) test, an automated assay for diagnosing mild traumatic brain injury. The submission compares the device to a predicate device, the BANYAN BTI™, and summarizes non-clinical and clinical testing results. The following points address the requested information based on the provided text:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly state "acceptance criteria" for each performance metric in a table format. However, it presents the results of various assays and often implies that the results "demonstrate" or "confirm" the required performance, indicating these are the achieved results compared to an internal standard or regulatory expectation. Below is a table summarizing various performance metrics and their reported results. Specific acceptance criteria values are not provided in this public summary.

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

• Test set sample size: For the diagnostic accuracy study, the sample size is not explicitly stated but refers to the "ALERT cohort." For the reference interval study, 513 apparently healthy US adult subjects were used.
• Data provenance: The diagnostic accuracy study was performed using the "ALERT cohort." The reference interval study was conducted at three sites (one internal European site and two external US sites). It is not specified whether these studies were retrospective or prospective, though "ALERT cohort" could suggest a pre-existing dataset.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g., radiologist with 10 years of experience)

This information is not provided in the document. The diagnostic accuracy study compares the device's results to the presence/absence of acute intracranial lesions visualized on a head CT scan, but the number or qualifications of experts interpreting these CT scans to establish ground truth are not mentioned.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

This information is not provided in the document.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

A multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This device is an in vitro diagnostic test for quantitative measurement of biomarkers, not an AI-assisted imaging device that impacts human reader performance.

6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done

Yes, the diagnostic accuracy study presents the standalone performance of the VIDAS® TBI (GFAP, UCH-L1) assay. The results (sensitivity, specificity, etc.) are based on the device's output compared to the ground truth (CT scan findings). The device is used "in conjunction with clinical information," but the reported diagnostic accuracy figures are for the test itself.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The ground truth for the diagnostic accuracy study was "absence of acute intracranial lesions visualized on a head CT scan." This indicates that CT scan results were used as the reference standard for traumatic brain injury assessment.

8. The sample size for the training set

This document describes a diagnostic device and its validation. It does not explicitly mention a "training set" in the context of machine learning or AI models with distinct training and test phases. The "test set" for diagnostic accuracy is referred to as the "ALERT cohort." The reference interval was established using 513 apparently healthy subjects.

9. How the ground truth for the training set was established

As there is no explicitly defined "training set" for an AI model in this submission, the method for establishing ground truth for a training set is not applicable or described. The clinical performance data presented (Diagnostic Accuracy and Reference interval) seems to represent the evaluation of the final device.

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