(27 days)
The BD Veritor™ System for Rapid Detection of Flu A+B is a rapid chromatographic immunoassay for the direct and qualitative detection of influenza A and B viral nucleoprotein antigens from nasopharyngeal wash, aspirate and swab in transport media samples from symptomatic patients. The BD Veritor System for Rapid Detection of Flu A+B is a differentiated test, such that influenza A viral antigens can be distinguished from influenza B viral antigens from a single processed sample using a single device. The test is to be used as an aid in the diagnosis of influenza A and B viral infections. A negative test is presumptive and it is recommended that these results be confirmed by viral culture or an FDA-cleared influenza A and B molecular assay. Outside the U.S. a negative test is presumptive and it is recommended that these results be confirmed by viral culture or a molecular assay cleared for diagnostic use in the country of use. FDA has not cleared this device outside the U.S. Negative test results do not prectude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. The test is not intended to detect influenza C antigens.
The BD Veritor™ Fly A+B test is an immunochromatographic assay for the qualitative detection of influenza A and B viral antigens in respiratory specimens. The patient specimen is added to a reaction tube prefilled with RV Reagent C. gently mixed, and then added to the test device. RV Reagent C contains mucolytic agents that function to break down mucus in a patient specimen thereby exposing viral antigens and enhancing detection on the assay device. Processed specimens are expressed through a filter tip into a single sample well on the BD Veritor™ Flu A+B test device.
After addition to the test device, any influenza B viral antigens present in the specimen bind to anti-influenza antibodies conjugated to detector particles on the Veritor ™ Flu A+B test strip. The antigen-conjugate complexes migrate across the test strip to the reaction area and are captured by a line of antibody striped on the membrane. The Veritor™ Flu A+B test devices are designed with five spatially-distinct zones including positive and negative control line positions, separate test line positions for the target analytes, and a background zone. The test lines for the target analytes are labeled on the test device as 'A' for Flu A position, and 'B' for Flu B position. The onboard positive control ensures the sample has flowed correctly and is indicated on the test device as 'C'. Two of the five distinct zones on the test device are not labeled. These two zones are an onboard negative control line and an assay background zone. The onboard negative control zone addresses non-specific signal generation. The remaining zone is used to measure the assay background.
The BD Veritor™ Flu A+B assay incorporates an active negative control feature in each test to identify and compensate for sample-related, nonspecific signal generation. The BD Veritor™ System Reader uses a proprietary algorithm that subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines. If the resultant test line signal is above a pre-selected assay cutoff, the specimen scores as positive. If the resultant test line signal is below the cutoff, the specimen scores as negative. Use of the active negative control feature allows the BD Veritor™ System reader to correctly interpret test results that cannot be scored visually because the human eve is unable to accurately perform the subtraction of the nonspecific signal.
Here's a breakdown of the acceptance criteria and study information for the BD Veritor™ System for Rapid Detection of Flu A + B Laboratory Kit, based on the provided document:
This document is a 510(k) summary for a modification to an already cleared device (K120049, K121797, K132256, K132693, K133138, K151301). The modification is specifically the addition of strain reactivity data for several influenza strains. Therefore, the core performance characteristics (sensitivity, specificity) of the device against a general population of influenza A and B are likely not re-evaluated in this specific submission. Instead, the focus is on demonstrating that the device still performs as expected with these new strains, effectively confirming continued substantial equivalence.
Given this context, the acceptance criteria and supporting "study" are focused on strain reactivity, not a full clinical performance study for initial clearance.
1. A table of acceptance criteria and the reported device performance
The document doesn't explicitly state quantitative acceptance criteria for strain reactivity, such as a minimum viral titer or a specific detection rate. However, the implicit acceptance criterion for the added strain reactivity data is that the device demonstrates reactivity to these strains, supporting that the device can still detect relevant circulating influenza viruses. The reported performance is simply the list of strains for which reactivity data has been added to the labeling.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Device demonstrates reactivity to newly identified strains. | Strains for which reactivity data was added: |
| - A/California/02/2014 (H3N2) | |
| - B/Brisbane/33/2008 (Victoria Lineage) | |
| - B/Guangdong-Liwan/1133/2014 (Yamagata Lineage) | |
| - B/Hong Kong/259/2010 (Victoria Lineage) | |
| - B/Texas/02/2013 (Victoria Lineage) | |
| - B/Utah/09/2014 (Yamagata Lineage) |
2. Sample size used for the test set and the data provenance
The document does not specify a "sample size" in terms of number of patient specimens for these strain reactivity studies. Instead, it refers to specific influenza strains. These would typically be cultured viral samples, likely tested at various concentrations to determine the limit of detection. The data provenance is implied to be laboratory testing of isolated viral strains. There is no information about the country of origin of the data or if it was retrospective or prospective in a clinical setting; it's likely laboratory-based in-vitro testing.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable for this type of strain reactivity study. Ground truth for viral strains is typically established through viral culture and sequencing, which would be performed in a laboratory by virologists or molecular scientists, not "experts" in the context of clinical interpretation.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set
Not applicable. Adjudication methods are typically for clinical studies where human interpretation of medical images or diagnostic tests is involved to establish a ground truth when a definitive gold standard is not available or to resolve discrepancies. For laboratory-based strain reactivity testing, the "truth" of the strain identification and concentration is determined through established virological and molecular methods.
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
Not applicable. This device is an immunoassay, not an AI-assisted diagnostic device, and this submission is not a comparative effectiveness study. It's a submission for adding strain reactivity data to the device labeling.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The BD Veritor™ System is a standalone diagnostic device. The BD Veritor™ System Reader uses a "proprietary algorithm that subtracts nonspecific signal at the negative control line from the signal present at both the Flu A and Flu B test lines" to provide a definitive positive/negative result. This implies an algorithm-only determination of the test result after the specimen is processed by the device. The human role is performing the test and reading the output from the device reader. The strain reactivity testing described would be solely based on the device's ability to detect the viral antigens of these strains, i.e., standalone performance.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The ground truth for the strain reactivity study is the identity and concentration of each specific influenza virus strain, confirmed typically by viral culture and molecular methods (e.g., genetic sequencing) in a laboratory setting. This is not expert consensus, pathology, or outcomes data.
8. The sample size for the training set
Not applicable. This device, being an immunoassay, is not an AI/machine learning device that requires a training set in the conventional sense. The "training" or development of the immunoassay itself relies on antigen-antibody interactions and assay optimization.
9. How the ground truth for the training set was established
Not applicable. (See #8).
§ 866.3328 Influenza virus antigen detection test system.
(a)
Identification. An influenza virus antigen detection test system is a device intended for the qualitative detection of influenza viral antigens directly from clinical specimens in patients with signs and symptoms of respiratory infection. The test aids in the diagnosis of influenza infection and provides epidemiological information on influenza. Due to the propensity of the virus to mutate, new strains emerge over time which may potentially affect the performance of these devices. Because influenza is highly contagious and may lead to an acute respiratory tract infection causing severe illness and even death, the accuracy of these devices has serious public health implications.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The device's sensitivity and specificity performance characteristics or positive percent agreement and negative percent agreement, for each specimen type claimed in the intended use of the device, must meet one of the following two minimum clinical performance criteria:
(i) For devices evaluated as compared to an FDA-cleared nucleic acid based-test or other currently appropriate and FDA accepted comparator method other than correctly performed viral culture method:
(A) The positive percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The negative percent agreement estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(ii) For devices evaluated as compared to correctly performed viral culture method as the comparator method:
(A) The sensitivity estimate for the device when testing for influenza A must be at the point estimate of at least 90 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 80 percent. The sensitivity estimate for the device when testing for influenza B must be at the point estimate of at least 80 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 70 percent.
(B) The specificity estimate for the device when testing for influenza A and influenza B must be at the point estimate of at least 95 percent with a lower bound of the 95 percent confidence interval that is greater than or equal to 90 percent.
(2) When performing testing to demonstrate the device meets the requirements in paragraph (b)(1) of this section, a currently appropriate and FDA accepted comparator method must be used to establish assay performance in clinical studies.
(3) Annual analytical reactivity testing of the device must be performed with contemporary influenza strains. This annual analytical reactivity testing must meet the following criteria:
(i) The appropriate strains to be tested will be identified by FDA in consultation with the Centers for Disease Control and Prevention (CDC) and sourced from CDC or an FDA-designated source. If the annual strains are not available from CDC, FDA will identify an alternative source for obtaining the requisite strains.
(ii) The testing must be conducted according to a standardized protocol considered and determined by FDA to be acceptable and appropriate.
(iii) By July 31 of each calendar year, the results of the last 3 years of annual analytical reactivity testing must be included as part of the device's labeling. If a device has not been on the market long enough for 3 years of annual analytical reactivity testing to have been conducted since the device received marketing authorization from FDA, then the results of every annual analytical reactivity testing since the device received marketing authorization from FDA must be included. The results must be presented as part of the device's labeling in a tabular format, which includes the detailed information for each virus tested as described in the certificate of authentication, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where the analytical reactivity testing data can be found; or
(B) In the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.
(4) If one of the actions listed at section 564(b)(1)(A)-(D) of the Federal Food, Drug, and Cosmetic Act occurs with respect to an influenza viral strain, or if the Secretary of Health and Human Services (HHS) determines, under section 319(a) of the Public Health Service Act, that a disease or disorder presents a public health emergency, or that a public health emergency otherwise exists, with respect to an influenza viral strain:
(i) Within 30 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation, the manufacturer must have testing performed on the device with those viral samples in accordance with a standardized protocol considered and determined by FDA to be acceptable and appropriate. The procedure and location of testing may depend on the nature of the emerging virus.
(ii) Within 60 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation and continuing until 3 years from that date, the results of the influenza emergency analytical reactivity testing, including the detailed information for the virus tested as described in the certificate of authentication, must be included as part of the device's labeling in a tabular format, either by:
(A) Placing the results directly in the device's § 809.10(b) of this chapter compliant labeling that physically accompanies the device in a separate section of the labeling where analytical reactivity testing data can be found, but separate from the annual analytical reactivity testing results; or
(B) In a section of the device's label or in other labeling that physically accompanies the device, prominently providing a hyperlink to the manufacturer's public Web site where the analytical reactivity testing data can be found. The manufacturer's home page, as well as the primary part of the manufacturer's Web site that discusses the device, must provide a prominently placed hyperlink to the Web page containing this information and must allow unrestricted viewing access.