(28 days)
The Alere BinaxNOW Influenza A & B Card 2 is an in vitro immunochromatographic assay for the qualitative detection of influenza A and B nucleoprotein antigens in nasopharyngeal (NP) swab and nasal swab specimens. It is intended to aid in the rapid differential diagnosis of influenza A and B viral infections. Negative test results are presumptive and should be confirmed by cell culture or an FDA-cleared influenza A and B molecular assay. Negative test results do not preclude influenza viral infection and should not be used as the sole basis for treatment or other patient management decisions. Alere BinaxNOW Influenza A & B Card 2 must be read by the Alere Reader.
Performance characteristics for influenza A were established during the 2015-2016 influenza A/H3N2 and A/H1N1 pandemic were the predominant influenza A viruses in circulation. When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent Influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
The Alere BinaxNOW® Influenza A & B Card 2 is an immunochromatographic membrane assay that detects influenza type A and B nucleoprotein antigens in respiratory specimens. Influenza specific antibodies and a control antibody are immobilized onto a membrane support as three distinct lines and combined with other reagents/pads to construct a test strip. The test strip is mounted inside a cardboard, book-shaped hinged test card.
Swab specimens require a sample preparation step, in which the sample is eluted off the swab into Elution Solution. Sample is added to the top of the test card is closed. Test results are interpreted at 15 minutes based on the presence or absence of Sample Lines. Alere BinaxNOW® Influenza A & B Card 2 test results must be read by the Alere™ Reader.
The Alere™ Reader is an easy to use bench top instrument that can be used near patient and in laboratory settings which will interpret, capture and transmit test results. The Alere™ Reader is a camera based instrument that detects the presence and identity of the Alere BinaxNOW® Influenza A& B Card 2 assay, analyzes the intensity of the test and control lines and displays the results (positive, neqative or invalid) on a display screen. The screen is intended as a means of user interface informing the user how to operate the Reader and to display test results, including any errors. Data can be retrieved and downloaded by the operator at any time after testing and uploaded to the hospital LIS/LIM system, if desired. Operator ID and Subject ID can be entered manually or via the provided barcode scanner. An external printer can be attached via USB to the Alere™ Reader to print test results.
A table of the acceptance criteria and the reported device performance is not explicitly provided in the text. However, the study aims to demonstrate that a software modification to the Alere™ Reader does not negatively impact the performance of the Alere BinaxNOW® Influenza A & B Card 2.
The study compared the performance of the Alere BinaxNOW® Influenza A & B Card 2 with the new software modification to the legally marketed predicate device (K173502). The core of the study involved testing clinical samples and comparing the results from the modified device with the predicate device.
Here's an analysis of the provided information concerning the study and ground truth:
-
Table of Acceptance Criteria and Reported Device Performance: This information is not directly presented as a table in the provided text. The submission describes a software modification to mitigate false positive results and states that the new device was compared to the predicate. To fully describe the acceptance criteria, one would typically need access to the original 510(k) submission (K173502) for the predicate device, as the current submission is a "Special 510k" focused on a software change, implying the goal is to maintain the performance of the predicate. The text states the study was performed to show that the modified software does not negatively impact performance and shows no statistically significant performance difference between the modified software and the predicate.
-
Sample Size used for the test set and the data provenance:
- The text states: "An evaluation was performed using 123 positive and 115 negative clinical samples..." This indicates a total of 238 clinical samples were used in the evaluation.
- Data Provenance: Not explicitly stated (e.g., country of origin). The data is from retrospective clinical samples as they were "clinical samples that were previously tested" with the predicate device.
-
Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not specified in the provided text.
-
Adjudication method for the test set: Not specified in the provided text.
-
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. The Alere Reader is an automated instrument, and the study compares two versions of the software in the instrument, not human readers with or without AI assistance. The reader performs the interpretation, so there's no human reading component for comparison in this context.
-
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Yes, the evaluation described is a standalone performance of the algorithm within the Alere™ Reader. The device reads and interprets the test result without human intervention for the reading step (the user interface displays the result, but the reading itself is automated).
-
The type of ground truth used: The ground truth for the clinical samples was based on "previously tested" results with the predicate device, implying a comparison to the established performance of the predicate. For the initial predicate device (K173502), the ground truth for influenza detection would typically be established by cell culture or an FDA-cleared influenza A and B molecular assay, as stated in the Indications for Use: "Negative test results are presumptive and should be confirmed by cell culture or an FDA-cleared influenza A and B molecular assay."
-
The sample size for the training set: Not specified. The submission describes a modification to existing software, implying the initial training would have occurred for the predicate device's software. This particular submission does not detail creation of a new training set.
-
How the ground truth for the training set was established: Not specified, as training set details are not provided in this document focused on a software modification. For the original validation of the predicate reader, the ground truth for training would likely have been established using well-characterized samples (e.g., confirmed by cell culture or molecular assay).
§ 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.