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The BD Veritor™ System for SARS-CoV-2 is a chromatographic digital immunoassay for the rapid, qualitative detection of SARS-CoV-2 nucleocapsid protein antigens directly in anterior nasal swab specimens from individuals with signs and symptoms of upper respiratory infection (i.e., symptomatic). The test is intended for use as an aid in the diagnosis of SARS-CoV-2 infections (COVID-19) in symptomatic individuals when either: tested at least twice over three days with at least 48 hours between tests; or when tested once, and negative by the BD Veritor™ System for SARS-CoV-2 and followed up with a molecular test.

A negative test result is presumptive and does not preclude SARS-CoV-2 infection; it is recommended these results be confirmed by a molecular SARS-CoV-2 assay.

Positive results do not rule out co-infection with other bacteria or viruses and should not be used as the sole basis for diagnosis, treatment, or other patient management decisions.

Performance characteristics for SARS-CoV-2 were established between April 2024 and August 2024 when SARS-CoV-2 Omicron was the predominant SARS-CoV-2 variant in circulation. Performance characteristics may vary with newly emerging SARS-CoV-2 virus variants.

The BD Veritor™ System for SARS-CoV-2 is a rapid (approximately 15 minutes) chromatographic digital immunoassay for the direct detection of the presence or absence of SARS-CoV-2 antigens in anterior nasal swab specimens taken from patients with signs and symptoms of upper respiratory infection (i.e., symptomatic) who are suspected of COVID-19 by their healthcare provider. The test is intended for use with an opto-electronic interpretation instrument, the BD Veritor™ Plus Analyzer Instrument and is not interpreted visually.

• When specimens are processed and added to the test device, SARS‑CoV‑2 antigens present in the specimen bind to biotinylated antibodies and antibodies conjugated to detector particles in the test strip.
• The biotinylated antibody‑antigen‑conjugate complexes migrate across the test strip to the reaction area and are captured by a line of streptavidin bound on the membrane.
• A positive result is determined by the BD Veritor™ Plus Analyzer when antigen‑conjugate is deposited at the Test "T" position and a control conjugate is deposited at the Control "C" position on the assay device.
• The instrument analyzes and corrects for non‑specific binding and detects positives not recognized by the unaided eye to provide an objective result.

Procedures to evaluate test devices depend on the BD Veritor™ Plus Analyzer workflow configuration chosen. In Analyze Now mode, the instrument evaluates assay devices after manual timing of their development. In Walk Away mode, devices are inserted immediately after application of the specimen, and timing of assay development and analysis is automated. Additionally, connection of a BD Veritor™ Plus Analyzer to a printer or IT system is possible if desired. Additional result documentation capabilities are possible with the integration of a BD Veritor™ barcode scanning enabled module.

The Analyzer uses a proprietary algorithm that subtracts the nonspecific signal at the negative control line from the signal present at the test line. If the resultant test line signal is above a preselected cutoff, the specimen is scored as positive. If the resultant test line signal is below or equal to the cutoff, the specimen is scored as negative. Use of the active negative control feature allows the BD Veritor™ Plus Analyzer to correctly interpret test results that cannot be scored visually because the human eye is unable to accurately perform the subtraction of the nonspecific signal. The Analyzer measures the amount of light reflected from various zones along the assay strip. The measurement of the assay background zone is an important factor during the test interpretation as the reflectance value is compared to that of the control and test zones.

The provided FDA 510(k) clearance letter and summary describe the BD Veritor System for SARS-CoV-2. Here's an analysis of the acceptance criteria and the study that proves the device meets those criteria:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated as distinct numerical targets in the document. However, based on the clinical study results and FDA clearance, the implicit acceptance criteria for clinical performance are related to the confidence intervals for Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA). The reported device performance is presented below:

Note: The document does not explicitly state numerical acceptance thresholds for PPA and NPA (e.g., "PPA must be > 80%"). Therefore, the "Implicit Acceptance Criteria" are inferred from the demonstrated performance and the fact that the device received clearance. The FDA typically evaluates these metrics within acceptable ranges for diagnostic tests.

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size for Test Set: 1,032 direct anterior nasal swabs.
• Data Provenance: The samples were prospectively collected from individual symptomatic patients across 15 geographically diverse areas across the United States between April and August 2024.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

The document does not specify the number of experts used to establish the ground truth. The ground truth was established by an FDA-cleared SARS-CoV-2 RT-PCR test. For the false positive/negative re-testing, it broadly states "a second RT-PCR method," implying multiple tests might have been performed to confirm results without specifying expert involvement in interpreting these specific results beyond the RT-PCR outcome itself.

4. Adjudication Method for the Test Set

The primary ground truth for the clinical study was established by an FDA-cleared SARS-CoV-2 RT-PCR test without explicit mention of expert adjudication for every case. However, there was a form of adjudication for discordant results:

• False Positive Adjudication: The three BD Veritor System for SARS-CoV-2 false positive results were retested with a second RT-PCR method and were confirmed negative. This suggests a method where initial discrepancies against the reference method were independently verified.
• False Negative Adjudication: The 23 BD Veritor System for SARS-CoV-2 false negative results were retested with a second RT-PCR method in which 14 were confirmed positive and 9 were negative.

This indicates a process of re-testing or confirmation for discordant results, which serves as a form of adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a multi-reader multi-case (MRMC) comparative effectiveness study comparing human readers with and without AI assistance (or similar comparative effectiveness of human readers with vs. without the device) was not explicitly mentioned or described in the provided document. The BD Veritor System for SARS-CoV-2 uses an instrument (BD Veritor™ Plus Analyzer) for interpretation, replacing visual interpretation with an automated read. The comparison is between the device's performance and a reference RT-PCR, not between human readers with and without assistance from the device.

6. Standalone (Algorithm Only) Performance Study

Yes, a standalone study was done. The entire clinical performance study (Table 9 and 11) is a standalone study, as it evaluates the performance of the BD Veritor System for SARS-CoV-2 (algorithm/device only) compared to a reference RT-PCR without human interpretation of the lateral flow assay itself. The BD Veritor™ Plus Analyzer instrument is explicitly stated to read and interpret the results, and the device "is not interpreted visually."

7. Type of Ground Truth Used

The ground truth used for the clinical study was an FDA-cleared SARS-CoV-2 RT-PCR test (molecular test results).

8. Sample Size for the Training Set

The document does not specify a sample size for a training set. This submission is for a device, and the analytical and clinical studies described are for validation of the device's performance, not for developing or training an AI/ML algorithm in the context of a typical AI/ML development pipeline. The device uses a "proprietary algorithm" for signal subtraction and interpretation, but it's not presented as a machine learning model that requires a distinct training set in the typical sense.

9. How the Ground Truth for the Training Set Was Established

Since no specific training set and its ground truth establishment are discussed in the context of AI/ML model training, this information is not applicable/provided based on the document. The "proprietary algorithm" for the instrument is described in terms of processing reflectance data and applying a preselected cutoff, and its development process (including any data used for internal calibration or parameter setting) is not detailed here.

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